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uu-fipcir 



111 



$B *H 311 



A DESCRIPTION 



MINERALS OF COMMERCIAL VALUE 



BARRINGER 



University of California. 



FROM THE LIBRARY OF 

Dr. JOSEPH LeCONTE. 

GIFT OF MRS. LECONTE. 
No. 






V 






With the Compliments of 



THE AUTHOR. 



r 



BY THE SAME AUTHOR. 



THE LAW OF MINES AND MINING 

IN THE 

UNITED STATES. 

BV 

DANIEL MOREAUX BARRINGER and JOHN STOKES ADAMS. 
1 Volume, 8vo. Sheep, $7.50, net. 



Published by LITTLE, BROWN & COMPANY, Boston. 



A DESCRIPTION 



OF 



MINERALS OF COMMERCIAL VALUE. 

A Practical Reference-book for the Miner \ Prospector, and Business Man, or 

any Person who may be interested in the Extraction or Treatment 

of the Various Metallic or Non-metallic Minerals, and for 

Students either in Field-work or in the Laboratory. 

BY 

D. M. BARRINGER, A.M., LL.B., 

One of the Authors of " The Law of Mines and Mining in the United States. 9 * 
FIRST EDITION. 



if * 



FIRST THOUSAND. 
NEW YORK: 

JOHN WILEY & SONS. 

London : CHAPMAN & HALL, Limited. 

1897. 



r 




Copyright, 1897, 

BY 

D. M. BARRINGER. 



ROBERT DRUMMOND, ELBCTROTYFIR AND PRINTER, HEW YORK. 



PREFACE. 



In the preparation of this little book the original intention of the author was to give in as simple and concise a form as 
possible a description of the nature of only the more important of those mineral substances, more frequently referred to as ores 
or compounds, which possess commercial value, indicating at the same time the means by which they could be identified, and refer- 
ring very briefly to some of the principal economic uses to which they are put. Upon reflection, however, it seemed advisable not 
to confine the work too strictly within this limitation, but to insert also a description of a few other minerals which are very fre- 
quently met with as common veinstones (i.e., gangue of the metallic ores) or as rock constituents, although they may possess in 
themselves little or no commercial worth. Outside of this he has not attempted to go, for by so doing he would be defeating 
the object he has had in mind, namely, to carefully exclude all minerals which do not fall under either of the above classifications 
— by far the greater number — and to thus confine himself to a brief working description of those which, for the reasons given, are 
directly or indirectly useful. 

The work is intended merely as a book of reference to be used by the practical miner or man of business, for whom espe- 
cially it is intended, as well as by the geologist, metallurgist, or mineralogist, in so far as it may serve their purposes. If the 
desired mineral be not enumerated in the following pages, or the information concerning it be not sufficiently complete, reference 

10 i loo _ 



r 



must be had to some of the many excellent and much more Comprehensive works upon mineralogy by such well-known authors ad 
Dana, Brush, Erni, von Kobell, Rutley, etc., from which this little volume has been very largely compiled.* 

In the arrangement of the material — that is, the grouping of the various ores or compounds under the element for the 
extraction of which they are chiefly mined — the author has adopted the simplest and most logical form which has occurred to 
him, and he hopes that it will meet with the approbation of the majority of those who may have occasion to refer to the following 
pages. 

D. M. Barringer. 

Bullitt Building, Philadelphia, June, 1897. 



* For fuller information concerning any mineral, its economic uses or mode of occurrence, the two following most excellent and modern works sbould be 
consulted : Dana's System 0/ Mineralogy (1897), and Roth well's Mineral Industry (in five volumes, 1892-1895). The latter work contains much very useful 
information concerning the occurrence, production, and uses of the various minerals of economic importance. The author wishes to acknowledge his indebted- 
ness to the authors of the above books, from which a very considerable portion of the information herein contained has been derived. See also the Geological 
Preface to The Law 0/ Mines and Mining in the United States (Barringer and Adams, 1897, published by Little, Brown & Co. of Boston), by the author of this 
work, which contains a detailed description ot the various kinds of ore deposits and their mode of occurrence in nature. 




A DESCRIPTION 

OF 

MINERALS OF COMMERCIAL VALUE. 



CONTENTS. 



PART I. PART II. 

I.— SYMBOLS AND ATOMIC WEIGHTS OF THE ELEMENTS. I.— TABLES OF MINERALS. 

II.— SYSTEMS OF CRYSTALLIZATION. II.-CLASSIFICATION OF MINERALS. 

HI.— SCALE OF HARDNESS III.— APPENDIX. 

IV.-SCALE OF FUSIBILITY. IV.— INDEX TO TABLES. 

V.-CHIEF DIVISIONS. 



PART 

I.-SYMBOLS AND ATOMIC WEIGHTS 



Aluminum 

Antimony (Stibium) 

Argon 

Arsenic 

Barium 

Beryllium 

Bismuth 

Boron 

Bromine 

Cadmium 

Caesium 

Calcium 

Carbon 

Cerium 

Chlorine 

Chromium .' . 

Cobalt 

Copper (Cuprum). . . 



Al 

Sb 

Ar 

As 

Ba 

Be 

Bi 

B 

Br 

Cd 

Cs 

Ca 

C 

Ce 

CI 

Cr 

Co 

Cu 



AT. WT. 

{afprox.). 



27 
119. 5 

19.8 (?) 

75 
137 
9 
207.5 

11 

80 
112 

132.7 

40 

12 
140 

35-5 
52 

58.7 
63 



Didymium 

Erbium 

Fluorine 

Gallium 

Germanium 

Gold (Aurum) , 

Hydrogen 

Indium 

Iodine 

Iridium 

Iron (Ferrum) 

Lanthanum 

Lead (Plumbum) 

Lithium 

Magnesium 

Manganese 

Mercury (Hydrargyrum) 



Di 

Eb 

F 

Ga 

Ge 

Au 

H 

In 

I 

Ir 

Fe 

La 

Pb 

Li 

Mg 

Mn 

Hg 



AT. WT. 

{approx.). 



1425 
166 

19 

70 

73-3 
197 
1 
H3-5 
126.5 
192-5 

56 

138.5 

206.5 

7 

24 

55 
200 



II.-SYSTEMS OF CRYSTALLIZATION. 

1. Isometric (e.g., cube and octahedron). — Three axes rectangular in intersections and equal. 

2. Tetragonal (e.g., right prism with square base). — Three axes rectangular in intersections — two lateral axes equal and 
unequal to the vertical, which may be longer or shorter. 

3. Hexagonal (e.g , rhombohedron and hexagonal prism). — The vertical axis, which may be longer or shorter than tho 
lateral, is at right angles to them; the lateral, which are equal, are three in number and intersect at angles of 6o°. 

6 



I. 



OF THE ELEMENTS. 



Molybdenum 

Nickel 

Niobium 

Nitrogen 

Osmium 

Oxygen 

Palladium 

Phosphorus 

Platinum 

Potassium (fCalium), 

Rhodium 

Rubidium 

Ruthenium 

Samarium 

Scandium 

Selenium 

Silicon 



Mo 

Ni 

Nb 

N 

Os 

O 

Pd 

P 

Pt 

K 

Rh 

Rb 

Ru 

Sa 

Sc 

Se 

Si 



AT. WT. 

(«r//r*r.). 



96 

58.5 

93-7 

14 
191 

16 
IO6.3 

31 
194-5 

39 
104 

85.2 
101.5 
149-6 

44 

79 

28 



Silver (Argentum). . . 
Sodium (Natrium), . . 

Strontium 

Sulphur 

Tantalum 

Tellurium 

Thallium 

Thorium 

Tin (Stannum) 

Titanium 

Tungsten ( Wolfram) 

Uranium 

Vanadium 

Ytterbium 

Yttrium 

Zinc 

Zirconium 



Ag 

Na 

Sr 

S 

Ta 

Te 

Tl 

Th 

Sn 

Ti 

W 

Ur 

V 

Yb 

Yt 

Zn 

Zr 



AT. WT. 
(afifirox.). 



I07.5 

23 

87.5 

32 
182 
127.6 
203.6 
'232 

117. 5 
48 

183.5 
240 

51 
172.6 

89.5 

65 

90.5 



4. Orthorhombic (e.g., right prism with rectangular or rhombic base). — The three axes rectangular in intersections and unequal. 

5. Mono clinic (e.g., right rhomboidal and oblique rhombic prisms).— Only one oblique inclination (one lateral axis inclined 
to the vertical) out of the three made by the intersecting axes, two being rectangular; the three axes are unequal. 

6. Triciinic (e.g., oblique asymmetric rhomboidal prisms). — All three axes unequal and their intersections are all oblique. 

111.-SCALE OF HARDNESS. 



1. Talc. 


2. Gypsum, Rock Salt. 


3. Calcite. 


4. Fluorite. 


5. Apatite. 


6. Feldspar. 


7. Quartz. 


8. Topaz. 

7 


9. Corundum, Sapphire. 


10. Diamond. 



* k 



IV.-SCALE OF FUSIBILTY. 

I. Stibnite. a. Natrolite. 3. Alumina-iron Garnet. 4. Actinolite. 5. Orthoclase. 6. Bronzlte* 

V.-CHIEF DIVISIONS. 

_ 1. 

ALUMINUM AND ITS COMPOUNDS. 

Heated on charcoal or in forceps in O. F. with cobalt nitrate and reheated gives a blue color. A blue infusible mass only 
indicates alumina. (See Heating with Cobalt Nitrate in Appendix.) 

2. 

ANTIMONY AND ITS COMPOUNDS. 

When strongly heated in closed tube yields a sublimate near assay which »s black when hot and brown-red when cold. 
Characteristic dense white fumes. On charcoal white sublimate near assay, bluish distant from assay ; crystals in coating far from 
assay are octahedrons ; those near assay needlelike (use lens). Sublimate less volatile than that of arsenious acid. H,S passed 
through acidified antimonial solution gives orange precipitate. Dissolved in aqua regia or hot H3SO4. When native takes fire 
and continues to burn without further heating, and becomes covered with white needles of antimony oxide. 

a, 

ARSENIC AND ITS COMPOUNDS. 

Heated on charcoal volatilizes with white incrustation, which is deposited far from assay, and which is easily driven off 
by the flame. When abundant easily recognized by garlic odor of the fumes. In closed tube gives brilliant black sublimate near 
assay with alliaceous fumes. When flame is applied to this sublimate it volatilizes, and the characteristic brilliant but minute 
octahedral crystals of oxide of arsenic are deposited further up the tube. 

8 



4. 
BISMUTH AND ITS COMPOUNDS. 

Its presence is detected by characteristic lemon or orange sublimate, which it and its compounds give when treated alone 
or with soda on charcoal before blowpipe. With sulphur and potassium iodide gives a scarlet coating far from the assay. Readily 
dissolved by nitric acid, which solution when concentrated gives white precipitate when poured into excess of water. The ores 
are rare. 



CALCIUM AND ITS COMPOUNDS. 

The presence of calcium may be often detected by the fine orange-red color which its compounds impart to blowpipe flame. 
Best, however, to test for it in the liquid way. Carbonate of ammonium produces in neutral calcium solutions a white precipitate 
(CaCOs) which is soluble in acids with effervescence (CO,). 

6. 
CHLOBIN12. >; 

This element, though not occurring in a free state in nature, is largely used and frequently met with through 
the many compounds which it forms, such as chloride of ammonium, copper, mercury, potassium, sodium, tin, silver, etc., 
which see. 

Chlorides when heated with strong sulphuric acid, save those of mercury, silver, and tin, evolve hydrochloric-acid gas, 
known by its pungent smell and acid reaction. When heated with peroxide of manganese and sulphuric acid chlorine gas is 
given off, recognizable by its irritant odor, green color, power of bleaching litmus, etc., and by the purple stain it produces on a piece 
of starch-paper moistened with iodide of potassium. When fused with a little carbonate of sodium and red chromate of potassium 
they furnish a mass which, when warmed with strong sulphuric acid, gives off deep red vapors of chromic chloride, CrOCU , 
decomposable by water to furnish an orange solution of mixed chromic and hydrochloric acids, becoming, not colorless, but only 
yellow, when rendered ammoniacal. (Odling.) Fused in a bead of microcosmic salt saturated with CuO imparts an azure-blue 
color to flame. 

9 — 



7. 
CHROMIUM AND ITS COMPOUNDS. 

Exists chiefly in two native compounds, viz., crocoite (Siberia) or chrotnate of lead \ and chromite or oxide of chromium and 
iron. It is, when reduced to metallic state, a whitish, brittle, and very infusible metal. Chief source is chromite, which is slightly 
magnetic. Fuses slightly, is soluble, and imparts a beautiful emerald-green color to beads of borax and salt of phosphorus when 
cold. 

8- 
COALS. 

These may be generally easily recognized by their physical characters, which are too well known to require description. 
" It passes from forms which still retain the original structure of the wood (peat % lignite) % and through those with less of volatile 
or bituminous matter to anthracite, and further to kinds which approach graphite " (Dana). Each species gives variable analyses 
according to amount of impurities present, etc., etc. 

Note. — A coking coal is a bituminous coal which softens or becomes pasty or semi-viscid in the fire. This is attended 
with escape of bubbles of gas. The volatile products resulting from the decomposition of the softened mass being driven off, a 
more or less coherent, grayish-black, cellular, or fritted mass is left, which is coke, or the part not volatile, and which varies from 
50 to 85 per cent. A non-coking % free-burning coal may be like the former in all external characteristics, and even in percentage of 
volatile matter and in general composition, but it burns freely without softening or any appearance of incipient fusion. The 
coke resulting from this is not a proper coke, being often in a powder or in the form of the original coal. (Dana.) 

9. 
COBALT AND ITS COMPOUNDS, 

Easily recognized by the characteristic deep sapphire-blue bead in both flames with borax or salt of phosphorus. The 
sulphurets should be roasted on charcoal before testing with borax, as in other metallic species. Dissolves in nitric acid. The 
insolubility of the black sulphides of nickel and cobalt in dilute HC1 suffices to separate these metals from the remaining members 
of the group. If ferrocyanide of potassium be added to solution, first made freely ammoniacal, a green precipitate is produced. 

10 



If ferrocyanide be added, the precipitate is brown-red. (Do not confound with similar precipitate of copper.) Sometimes associ- 
ated with oxides of manganese. (Missouri and South Carolina.) Largely associated with arsenic, but the blue color of bead 
suffices to readily distinguish them from arsenopyrite. 

10. 
COPPEK AND ITS COMPOUNDS. 

Borax bead in O. F. is green when hot, and greenish-blue when cold ; in R. F. colorless if saturation be weak, but red 
with strong saturation when hot ; metallic copper and copper-red when cold. On charcoal with soda a copper-colored globule is 
obtained. When combined with the oxides, tin and borax should be used. When ammonia in excess is added to nitric acid solu- 
tion, the liquid is colored blue ; metallic copper is deposited on iron wire or a nail immersed in this. Specimens should be roasted 
before making B. B. test with borax. For traces of copper place drop of suspected solution on platinum foil. Place in this a 
piece of zinc; a film of copper will be deposited on the platinum foil at point of contact. Copper compounds moistened *vith a 
drop of HC1 and ignited B. B. color the flame azure-blue. 

11. 
GOLD AND ITS COMPOUNDS. 

Gold may be generally recognized by its physical characters— color, lustre, malleability, and specific gravity. When a 
gold compound is heated on a carbonized match or charcoal in R. F., a yellow malleable bead is obtained which dissolves in aqua 
regia. If this solution be dropped on to a filter-paper, and one drop of stannous chloride be added, a purple-red color is obtained. 
Gold can be readily detected in its solutions, inasmuch as it is obtained in a metallic state by reducing agents. The well-washed 
precipitate being dissolved^ and tested with stannous chloride, it is separated from the easily volatile metals by simply heating on 
charcoal in O. F. If associated with copper or silver, it must be fused with a large excess of pure metallic lead and subjected to 
cupellation. The copper is absorbed into the cupel with the lead, while the silver remains alloyed with the gold. If the globule 
is quite yellow, this is a proof that but little silver is present. It is then to be tested with salt of phosphorus to prove the presence 
of silver, which, after fusing on charcoal in O. F., will impart an opaline character to the cool bead. If it be more of a silver- 
white color, the amount of gold will be small ; and in order to prove its presence and approximate quantity, the globule must be 
digested with nitric acid by application of heat. The silver is thus dissolved, and the gold remains as a dark powder or spongy 
mass. If this powder or mass be washed and fused with borax on charcoal, it will yield a globule of metallic gold, 

u 



12. 
HYDROCARBONS. 

Compounds of carbon, hydrogen, and oxygen. These compounds are numerous, and form a great variety of economically 
important gaseous, liquid, and solid products, the composition and characters of the more prominent among which are stated under 
their proper heads. For sake of distinguishing between them the various coals are placed in a separate division, although they 
are also oxygenated hydrocarbons — one point of difference being that the substances here enumerated generally yield large quanti- 
ties of paraffine, while this can be said of only few of the coals. While the latter chemically considered possess many character- 
istics in common with, they differ widely in physical and in other respects from, the varieties enumerated in the tables under this 
division. 

ia. 

IRON AND ITS COMPOUNDS. 

With borax in O. F. oxide of iron gives a dark brown-red glass, which becomes pale-yellowish or colorless on cooling ; in 
R. F. bottle-green on cooling. With tin the green color is hastened. Most of the compounds become magnetic when heated with 
soda on charcoal. Dissolve readily in HC1. Sulphide of ammonium gives to their solution a black precipitate, which is soluble 
in dilute HC1, distinguishing it from cobalt and nickel. Another excellent test is to add ferrocyanide of potassium to solution. 
A pale-blue precipitate indicates ferrous salts, and a dark-blue precipitate ferric salts, of iron. The presence of titanium may be 
delected by the fact that the borax or salt of phosphorus bead becomes violet-blue or reddish purple when the R. F. is directed 
upon it, especially if tin be added, and test made on charcoal. A better test is to add tin to concentrated HC1 solution, and 
continue to boil. Set aside. If titanium is present, the solution becomes violet in color. The presence of chromium is also 
readily detected. (See Chromic Iron.) 

14. 
LEAD AND ITS COMPOUNDS. 

They are easily fusible. With borax bead and with soda, ana oiten alone, on charcoal, a malleable bead may be obtained. 
Readily recognized by characteristic lemon- or sulphur yellow coating near assay when cold ; red when hot. The outer coating is 



faintly bluish white when cold. When S and KI are added there is a greenish-yellow coating far from assay. Sublimes readily. 
Volatile, tinging flames azure-blue. In nitric-acid solution of salts of lead sulphuric acid gives a white precipitate, which is nearly 
insoluble in water and dilute acids. Heated in open tube white smoke and a non-volatile fusible sublimate is deposited on under 
side of tube. Oxides, carbonates, etc., may be reduced to the metallic state by heating in R. F. with soda, and the characteristic 
coating will be produced on the coal. But sulphides, arsenides, etc., of lead must be treated in O. F. to produce the metal. 
Metallic lead obtained as above may be cupelled for silver on charcoal, or, better, on a bone-ash cupel. (See B. B. Silver Assay, 
Appendix.) 

15. 
MAGNESIUM AND ITS COMPOUNDS. 

These afford a clear rose-red or pink color with cobalt nitrate after long heating. This distinguishes it from alumina. 
Distinguished from strontia and baryta by different flame-colors, and in the wet way by the fact that sulphuric acid gives no 
precipitate in dilute HC1 solution. The fact that the precipitate from magnesia is soluble in water, while that from calcium is 
not, suffices to distinguish it from the latter, etc. 

16. 

MANGANESE AND ITS COMPOUNDS. 

These are readily recognized by the characteristic amethystine color oxide of manganese imparts to beads of borax and 
salt of phosphorus in O. F. ; colorless in R. F. With borax the color becomes violet, amethystine, or purple when hot ; amethys- 
tine when cold. With salt of phosphorus, brown-violet when hot ; pale red-violet when cold. Do not confuse with pale-violet 
color imparted to beads by presence of titanic acid, which only appears on heating in R. F. Too large a quantity renders bead 
opaque. With soda in O. F. on platinum wire or, preferably, platinum foil, the color is green or bluish green. Most varieties are 
soluble in hydrochloric acid with evolution of chlorine. The oxides are frequently associated with ores of iron, especially brown 
hematite (limonite), and less often with varieties of red hematite or mugnctite 

13 



17. 
MEBCURY AND ITS COMPOUNDS. 

Mercury and amalgams volatilize on charcoal, but give a sublimate of metallic mercury when heated in closed tube with 
or without soda ; best with soda. The metal condenses above assay in globules on the tube. These may be brushed together 
with a feather, etc. When a gray sublimate is obtained without distinct metallic globules, the part of the tube coated with it is 
cut off and boiled in a test* tube with a little dilute HC1. By this treatment mercury collects in shining globules. In case mer- 
cury exists in so small a quantity that the sublimed metal is not perceptible, it may be detected by inserting a piece of gold-leaf 
held on end of iron wire into the tube just above assay. On heating the mercury is volatilized and unites with the gold, giving it 
a wnite color. 

18. 
MOLYBDENUM AND ITS COMPOUNDS. 

With borax bead in O. F. colorless when hot ; faint yellow when cold. With saturation the bead becomes in R. F. an 
opaque black or bluish to green enamel when cold. 

19. 
NICKEL AND ITS COMPOUNDS. 

With borax the presence of nickel in O. F. renders bead, when hot, purplish, with tinge of violet ; when cold, reddish 
sherry-brown. In R. F. the bead becomes purplish gray and turbid, with reduced nickel (use lens). If a fragment of nitre be 
added and the bead be again heated in O. F.,a well-marked purple color is produced. Roast before making above tests. Arseni- 
cal compounds of nickel, cobalt, iron, and copper are treated with glass of borax (see Cobalt) ; when borax is no longer colored 
blue from cobalt, but acquires a brown color, which is violet when hot, the metallic globule is separated from the borax and treated 
with salt of phosphorus in O. F. If copper, as well as nickel, be present in the assay, the glass thus obtained will be green while 
both hot and cold. Treated with tin on charcoal it will become red and opaque on cooling. Black sulphides insoluble in dilute 
HC1. (See Cobalt.) Nitric solutions are apple-green. Excess of ammonia produces a violet-blue liquid, from which caustic 
potash slowly precipitates the green hydrate of nickel. Potash produces this precipitate from all ordinary nickel solutions. 
^ 14 



20. 
PHOSPHATE BOCK. 

Mineral variety, apatite, which see. Common variety, often replacement of CaCOs by phosphate of lime ; also includes 
fossil teeth, bones, etc. The substance examined for phosphorus is mixed with soda, as for sulphur (3 soda, 1 substance). A 
thin glass tube closed at one end has a piece of magnesium wire or ribbon, one-half inch long, dropped into it. Then the mixed 
soda and substance is added so as to cover the magnesium. Heat to fusion the contents of the tube until the glass is attacked. 
While still red plunge under water in a small vessel, and immediately apply the nose. The characteristic odor of hydrogen phos- 
phide is evolved. 

Precautions. — Heat to full fusion. Do not have too much water in vessel ; see that end of tube is broken. The above 
test is not delicate enough for minute quantities, as in Bessemer-iron ores. In examining iron ores for phosphorus try to find 
small grains of apatite, and test as above. Best test is to add molybdate of ammonium to nitric-acid solution. An abundant bright 
yellow precipitate (phospho-molybdatc of ammonium) indicates character of the specimen. 

21. 
SILVER AND ITS COMPOUNDS. 

Silver compounds when fused with soda on charcoal yield a hard, white, malleable button, usually without any incrusta- 
tion on the coal, bat when treated for a long time with the reducing flame a slight dark-red coating is produced. When associated 
with volatile and easily oxidizable metals it may be separated by heating on charcoal in O. F., but if associated with large quanti- 
ties of lead or bismuth it is best to subject it to cupellation. (See Appendix.) HC1 gives in a solution of silver a white heavy 
precipitate of AgCl, which is insoluble in boiling nitric acid, but readily soluble in ammonia. The color of the precipitate changes 
to slate-purple by exposure to light. This is a distinguishing characteristic. 

22. 
SULPHUR AND SULPHIDES. 

The following is usually sufficient to detect the presence of sulphur. Mix the substances suspected to contain sulphur with 
soda (3 soda, 1 substance), and heat on platinum wire or charcoal in R. F. The fused mass is then crushed on a clean piece of 

15 



silver (coin or plate), and a drop of water added. A yellowish stain on the silver indicates a trace of sulphur ; larger quantities 
give a brown or a black stain. Sulphides such as pyrites, galena, etc., heated on charcoal give the odor of burning sulphur. 
Mixed with soda as above and heated in O. F. on platinum wire, the sulphides color the coin brown to black ; but sulphates, 
gypsum, baryta, etc., so treated in O. F., do not color the coin ; in R. F., however, the sulphate is changed to sulphide and colors 
the coin. Sulphides or substances containing sulphides in considerable quantities yield sulphur dioxide when heated in open 
tube. The sulphur dioxide may be recognized by its odor and by reddening, and sometimes bleaching blue litmus-paper inserted 
in end of tube. Usually soluble in nitro-hydrochloric or concentrated nitric acid. Some are extremely difficult to dissolve com- 
pletely, owing to the deposition of sulphur, which fuses around the unaltered substance and prevents any action of the acid 
upon it, but these can usually be recognized by their volatility, etc. (mercury, arsenic, etc.). The higher sulphides give off sulphur 
when heated in closed tube. Free sulphur fuses and sublimes, and on charcoal burns with a blue flame, and affords odor of 
burning sulphur. 

23. 

TELLUBIUM AND ITS COMPOUNDS. 

Of no use in the arts. Rarely occurs native, when it is a white and brittle metal, which is easily fusible, with greenish 
flame. It fumes strongly, and, in presence of selenium, gives the peculiar odor of decomposing horse-radish. Usually combined 
with the other metals as tellurides of gold, silver, lead, and bismuth, which see. In open tube a white or grayish sublimate is 
obtained, which may be fused to clear, colorless drops. Soluble in nitric acid. 

24. 
TIN AND ITS COMPOUNDS. 

Fused with soda and borax on charcoal in R. F„ the compounds of tin yield a globule of the metal. At the same time a 
coating is formed on the coal which is slightly yellow when hot, but white when cold. To obtain a coating, however, the assay 
must be kept covered with the blue R. F. The coating moistened with cobalt solution, and heated in the O. F., assumes a bluish- 
green color. Sulphides should always be roasted. When a solution of salts of tin, acidulated with HO, is brought in contact 
with metallic zinc, metallic tin is thrown down in the form of scales or as a gray spongy mass. 

10 



25. 
TUNGSTEN AND ITS COMPOUNDS. 

Before blowpipe compounds of tungsten impart to salt-of-phosphorus bead at first a dirty green, then a blue color when 
cold. If iron is present, the bead appears blood-red. Best with tin on charcoal. Characteristic reaction is that when boiled 
with phosphoric acid its compounds give a beautiful blue sirup. Often associated with tin ores. 

26. 
ZINC AND ITS COMPOUNDS. 

Compounds of zinc with borax give a clear glass, which is milk-white on flaming, or with more assay becomes enamel- 
white on cooling. In the R. F. on charcoal burns with a greenish-blue flame. Fumes are given off, depositing muck oxide, which 
coating is yellow when hot, but white when cold. With soda on charcoal the ores, even when containing little zinc, afford the 
peculiar bluish flame of burning zinc, and the oxide is deposited on the coal. When this coating is moistened with cobalt nitrate, 
a fine yellowish or dirty-green color is obtained (either alone or with soda), while tin gives a bluish-green color when similarly 
treated. 

END OF PART I. 



17 



PART II. 

I.— TABLES. 



Nam.. 



COMP. AND 

Percentage 
of Important 

COMtnTVBNT. 



Specific 



General Characters and Associations. 



Bbforb Blowpipe. 



ALUMOnTM AND ITS COMPOUNDS. 

Heated on charcoal or forceps in O. F. with cobalt nitrate and reheated gives a blue color. A blue infusible mass only 
Forms many useful alloys, e.g., aluminum bronze and ferro-aluminum in making and easting steel, etc. Many articles are made entirely 
forms, suck as ingots, skeets, wire, etc. Its ores, especially bauxite, are also largely used for tke manufacture of aluminum salts or 

Occurs as irregularly round concretions — rarely amorphous. Concretionary structure never wholly absent 
Pebble-like, pisolitic, oolitic, vesicular, and amorphous. Origin ascribed to deposition of solutions con- 
tained in waters of thermal springs and geysers, though often due to decay of certain rocks, and found 
in the residual clay. Gives much water in closed tube. Common impurities — silica, iron, and titanic 
acid. Other accidental impurities are phosphoric acid, sulphuric acid, carbonic acid, lime, magnesia, 
etc. Presence of titanium characteristic. (Compare kaolinite.) Some European deposits form more or 
less stratified beds, but thq (jreorgia and Alabama deposits are superficial and pockety. Deposits in these 
states usually occur in connection with Silurian rocks (dolomite), but supposed to have been formed in 
Tertiary times. French deposits occur in connection with Cretaceous limestone and are interbedded 
with lacustral formations. (See 16th An. Rep. U. S. Geol. Sur., part in — Mineral Resources, 1894, p. 
547 et sea.) Frequently associated with iron ore and sometimes mistaken for honeycombed impure 
iron ore. 



The ores 


AUO,, 


of Alu- 


H.O, or 


minum 


Al,Fe s O> 


are: 


+ 2H.O. 




Variable. 


Bauxite. 


Aluminum 




from 20 to 




40*. 




sometimes 




much more 


- Cryolite. 


Na.Al.F,,. 




Aluminum 




12.8*. 




Sodium 




32.8*. 




Fluorine 




5*4*. 



Easily fusible in flame of candle. Massive, cleavable, brittle, 
fracture uneven. Only workable quantities known in Green- 
land. Said to be found there in a large vein in gneiss, and to 
be associated with galena, blende, siderite, cassiterite, pyrites, 
fluor-spar, etc. Also sparingly in quartz veins in granite in 
Colorado. 



In the forceps fuses easily, coloring 
flame yellow. On charcoal fuses to 
a clear bead which becomes opaque 
on cooling. In the open tube when 
so heated that the flame enters the 
tube, hydrofluoric acid is driven off, 
etching the glass. 



20 



Characters. 



Treatment with Acids,btc. 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard* 
ness. 



Sr. Gk. 



CRYS- 
TALLI- 
ZATION. 



Magnetic 

BEFORE 
OR AFTER 

Heating. 



Uses, 



indicates alumina. (Se« Heating with Cobalt Nitrate in Appendix.)-^— ^ Uses.- Of rapidly increasing commercial importance, 
from it where light weight, durability \ and non-liability to tarnish, as well as other metallic attributes % are desirable. Made into many 
s compounds, especially alums. 



HC1 affects it but little, White, 



Dull. - Earthy Infus. Vari- 
or able, 

above 
5- 



a. 55 



while concentrated 


brown, and 




of 


phosphoric acid dis- 


red to black. 




like 


solves it almost en- 


Also cream- 




color. 


tirely. Soluble also 
in sulphuric acid. 


or pearl- 
white, gray- 
ish, yellow- 
ish, amber, 
pinkish. 
Frequently 
mottled and 
iron-stained 






tfo effervescence when 


White, red- 


Vitre- 


White, 


heated with HC1. Sol- 


dish to 


ous to 


etc 


uble in sulphuric acid 
with evolution of hy- 
drofluoric acid. 


brownish, 
and rarely 
black. 


greasy. 





2.5 



Usually In addition to being used as 
slightly an ore of aluminum, it is 
after. very largely used in the man- 

ufacture of alum, for which 
purpose the insoluble matter 
should not exceed 7^, nor the 
oxide of iron 2.75^. Also used 
in the manufacture of very 
high-grade and refractory 
crucibles and fire-brick. 



In addition to being to a lim- 
ited extent an ore of alumi- 
num, and used in the manu- 
facture of alums, cryolite 
is used in the manufacture 
of a porcelain-like glass. It 
is also used in the manu- 
facture of chemically pure 
soda. 



21 



Name. 



Alum. 



Com p. and 
•percentage 
op Important 
Constituent. 

Very vari- 
able. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



Generally fuses in its own water of 
crystallization and froths, forming 
a spongy mass. Intense blue when 
moistened with cobalt solution, 
charcoal forms a hepatic mass. 



On 



The alums proper, which may be fibrous or massive or mealy or in 

solid crusts, are hydrous sulphates of alumina with an alkali metal 

and 24 molecules of water. Thus potash alum (kalinite) has 

formula K t S04Al*(S0 4 )s -f 24H..O, while soda alum (mendozite) 

has formula Na,S0 4 , A1,(S0 4 ),+24H»0. That is to say, the former 

contains sulphur trioxide, 33.7; alumina, 10.8; potash, 9.9; water, 

45-6; and the latter contains sulphur trioxide, 34.9; alumina, 11.1; 

soda, 6.8; water, 47.2. The former is much more common. Alum 

effloresces on argillaceous minerals and particularly alum shales. 

More or less common. A more or less common variety is halo- 

trichite, or iron alum, where either magnesium, iron, manganese, 

etc., are present; e.g., samples from New Mexico contain sulphur 

trioxide, 37*19; alumina, 7.27; iron protoxide, 13.59; insoluble, 

0.50. (Dana.) 
Note. — Ammonia alum (comparatively rare in nature) is now ex- 
tensively manufactured from the waste of gas-works, and is used 

in the place of potash alum. 

ANTIMONY AND ITS COMPOUNDS. 

Native Sb. When strongly heated in closed tube yields a sublimate near assay, which is black when hot and 

(rare). crystals in coating far from assay are octahedrons; those near assay needle-like (use lens). Sublimate 

in aqua regia or hot H»S0 4 . When native takes fire and continues to burn without further heating, 
in general rendering metals more lustrous, hard t and brittle. When alloyed with lead it is largely used in the 
to a small extent in medicine. Alloyed with lead it is also used in alkali-works for making pu^mps and taps for 
Sometimes occurs in nature alloyed with other metals, such as 
arsenic, silver, and nickel. ' 



CHARACTERS. 



Treatment wrm Acixm,btc 

Generally soluble in 20 
times its weight of 
cold water, and very 
much less in boiling 
water. 



COLOE. 


Lustre. 


Streak 


Fuu- 

B1UTY. 


Hard- 
ness. 


Sr. Gr. 


Crys- 
talli- 
zation. 


Generally 
white to 
yellowish 
white. 


Vitreous 
to silky. 
Trans- 
parent 
and 

translu- 
cent, but 
varie- 
ties be- 
come 
dull on 
expos- 
ure. 


White 


Easily 


*-3 


1.75- 
I.90 


I, also 
Vand 
VI. 



Magnetic 
bkforh 

OR AFTER 

Heating. 



Uses. 



Used in the manufacture of 
paper, dyes, and baking-pow- 
ders; also in tanning leather, 
and in clarifying or filtering 
turbid or impure water. Alu- 
minate of sodium is used in 
calico-printing and the sa- 
ponification of fats, and in 
the manufacture of stearine 
candles, etc. 



brown-red when cold. Characteristic dense white fumes. On charcoal white sublimate near assay, bluish distant from assay; 
less volatile than that of arsenious acid. H»S passed through acidified antimonial solution gives orange precipitate. Dissolved 
and becomes covered with white needles of antimony oxide. ■ Uses . — Its chief use is as an alloy with other metals \ an admixture 

manufacture of type-metal. It also forms part of the anti-friction metals, such as babbitt metal, employed for bearings in machinery \ and 
raising and drawing off acids. 



Name. 



COMP. AND 

Percentage 
op Impost ant 

CONSTITUENT. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



A1TFIMONY AND 

SbjSj. 



Stibnite. 
(Anti- 
mony 
Glance). 
The oth- 
er ores 
are com- 
parately 
rare. 



Antimony, 
71-4*. 



ITS COMPOUNDS.— Continued. 

Burns in flame of candle. Slightly sectile. Almost the entire 
supply of commerce is derived from this ore. 

Usually associated with silver, lead, copper, etc., in many veins 
and other classes of deposits in which the ores of these metals 
occur. Frequently met with throughout the Rocky Mountain 
region. Occurs with quartz in veins in clay-slate in Arkansas, 
but, tike the other ores with which it is found, occurs in many 
kinds of rock. 



Volatilizes and gives off white fumes 
and a sulphurous odor. Fuses 
easily and colors flame greenish 
blue. On charcoal fuses and gives 
white coating which volatilizes 
when R. F. is turned upon it, color- 
ing flame green-blue. 



i^ervan- 
tite 


dDiU 4 * 


(Ker 
mesite) 
(Sb.OS.) 
is cher- 


Antimony, 
78.9*. 


ry-red 
variety. 




(White 


Sb t O>. 


anti- 




mony) 
Valen- 
tinite. 


Antimony, 
83.3*. 



Antimony oxide resulting from decomposition of stibnite and other Infusible, but easily reduced on char- 
ores of antimony. coal. 



Becomes yellow in flame of candle and fuses to a white mass. 
Translucent to subtransparent. 



Much the same as stibnite. 



U 



ChaBACTKBS. 



Treatment wim Acids,bxc. 



In closed tube, black to 
brown sublimate when 
hot, which becomes 
brown-red on cooling. 
Yellow sublimate of 
sulphur further up the 
tube. When pulver- 
ized and treated with 
potassa is rapidly col- 
ored ochre-yellow and 
mostly dissolved. Sol- 
uble in hydrochloric 
acid when pure. 



Color. 


Lustrb. 


Stbbak 


Fusi- 
bility. 


Lead-gray to 


Metal- 


Gray 

and 


I 


steel-gray. 


lic to 






splen- 


shin- 






dent. 


ing 
tar- 
nish. 
Like 
color. 





Habd- 



Sp. Gb. 



4-5 



Cbys- 

TAU.I- 
ZATION. 



IV. 



Magkxtic 
bbpobb 

OB AFTBB 
H BATING. 



USBS. i 



See under heading Antimony, 
etc. 



Reacts for antimony. 


Yellow, 


Pearly 


Yel- 


Infu- 


Soluble in HC1. 


white, and 


or 


lowish 


sible. 




reddish 


greasy, 


white 






white. 


some- 
times 


to 
white 





4-5 



4.08 



IV. 



See under heading Antimony, 
etc. 



earthy. 



Insoluble in water. 
Dissolves readily in 
HC1 without evolu- 
tion of gas. 



White, 
sometimes 
red or gray. 



Pearly 
or ada- 
mantine 



White 



3.5 



5.57 



IV. 



See under heading Antimony, 
etc. 



85 



Name. 



COMP. AND 
PERCENTAGE 

op Important 
Constituent, 



Specific 



General Characters and Association*. 



Before Blowpipe. 



ANTIMONY AND ITS COMPOUNDS.— Continued. 

Ker- SbiOSi. Oxysulphide resulting from decomposition of stibnite, etc. 

mesite — 

cherry- Antimony, 
red vari- 75*. 

ety. 

Apatite 3Ca a PiO» Reacts for phosphorus. (See phosphate rock.) Distinguished 
(Phos- 4~ CaFj. from beryl by its inferior hardness, being easily scratched with 

phorite). a knife; from calcite by no effervescence with acids; from pyro- 

Phosphate morphite (lead phosphate) by its difficult fusibility, and giving 

of lime, B. B. no metallic reaction. The last affords B. B. a globule 

92.25*. which becomes angular or crystalline on cooling. Brittle, trans- 
parent to opaque. 
Occurs in rocks of various kinds, but more frequently in those of 
a metamorphic crystalline character, as in Laurentian gneiss, 
which is usually hornblendic, granitic, or quartzose in character, 
in Canada, and in association with granular limestone. Also 
found in veins traversing granite and in many metalliferous 
veins, also disseminated in beds of iron ore and in mica schist, 
and sometimes associated with tin in gneiss, syenite, etc. Fre- 
quently found associated with such minerals as pyroxene, amphi- 
bole, titanite, zircon, garnet, etc., etc. 



On charcoal much the same as stib- 
nite. 



In forceps infusible except at edges, 
coloring flame reddish yellow; 
moistened with H*SO« colors flame 
feebly green. 



Characters. 

treatment with aod»,etc. 



Color. 



Lustre. Streak 



Fum- 



' Hard- 
ness. 



Sr. Gr. 



Crvs- 

TALU- 

ZATION. 



Magnetic 
before 

OR AFTER 

Heating. 



Uses. 



Ii» open tube 
like stibnite. 



reacts 



Slowly soluble In nitric 
acid. - Insoluble in di- 
lute HC1. Acetate of 
lead added to nitric 
solution (not too acid) 
causes a heavy pre- 
cipitate of phosphate 
of lead. Molybdate 
of ammonium added to 
solution gives a bright 
yellow precipitate. In 
a closed tube it affords 
no water. 



Cherry-red. 


Ada- 


Brown- 


t 




mantine 


red. 






to me- 








tallic. 






Variable, but 


Vitre- 


Whit- 


Quiet- 
ly at 


generally 


ous, 


ish. 


tinged sea- 


never 




5- 


green or 


bright, 






grayish 


inclin- 






green, yel- 


ing to 






low, blue, 


'Sub- 






brown, red 


resinous 






and gray, 




' 




sometimes 








colorless. 









1-5 



4.6 



3.20 



III. 



See under heading Antimony, 
etc. 



The principal use of apatite 
is as a source of phosphoric 
acid and phosphorus, and 
before the discovery of the 
phosphate-rock deposits in 
Florida was largely sold to 
the manufacturers of fertil- 
izers, its value for them, as 
in the case ' of phosphate 
rock, depending upon the 
percentage of phosphate of 
lime which it contains. (See 
phosphate rock.) 



*r 



Name. 



Com p. and 
Percentage 
or Important 
Constituent. 



Specific 



General Characters and. Associations. 



Before Blowpipe. 



ARSENIC AND ITS COMPOUNDS. 

Heated on charcoal volatilizes with white incrustation, which is deposited far from assay, and which Is easily driven off oy 
assay, with alliaceous fumes. When flame is applied to this sublimate it volatilizes, and the characteristic brilliant but minute 
small quantities are mixed with lead it is used in the manufacture of small shot. When added to iron and steel it is used for the manu- 
useful articles being made from the alloy. Also used to a certain extent in agriculture \ in the manufacture of certain kinds of glass \ and 

Note. — Considerable quantities are now obtained from the reduction of cobalt and nickel ores as a by-product. 



Native. As. 



\rseno- 


FeAsS. 


pyritc 
(Mis- 
picket). 


Arsenic, 
46.0*. 



Orpi- 
ment. 



As,S«. 

Arsenic, 
61.0* 



Very brittle and friable. Easily pulverized/ Soon oxidizes on 

exposure, producing black crust. 
Occurs principally in veins in crystalline rocks associated with 

ores of antimony, lead, silver, etc. 



Common ore. Brittle. When associated with nickel and cobalt 

ores it reacts for these two metals. 
Found principally in crystalline rocks, associated with ores of lead, 

silver, tin, also with pyrite, chalcopyrite, and sphalerite. 



Small crystals with smooth surface, and irregularly clustered 

together or in foliated or fibrous masses. 
Found associated with realgar, native arsenic, and calclte. 



Volatilizes at 356° without under- 
going fusion, and burns with pale- 
bluish flame when heated just 
. below redness. Gives a white 
' coating on coal, and affords a garlic 
odor. 

Gives fumes of arsenic; InR. F. be* 
comes black and attractable by tht 
magnet, owing to presence of iron. 
In closed tube first red sublimate, 
then lustrous black sublimate of 
metallic arsenic; in open tube sul- 
phurous fumes and white sublimate 
of arsenic trioxide. 

Reacts for arsenic and sulphur. Fuses 
readily and volatilizes, and with 
soda on charcoal gives arsenical 
fumes and a blue flame. 



Characters. 



TREATMENT WITH ACIM,BTC. 



Color. 



Lustre, Streak 



FUSI- 
BILITY. 



Hard- 



Sk G*. 



Magnetic 
brpore 

• *«.«.... OR AFTER 

XATION. HtATINC. 



CrYS- 
TALLI- 



Ustt. 



the flame. When abundant easily recognized by garlic odor of the fume,s. 
octahedral crystals of oxide, of arsenic are deposited further up the tube. — 



In closed tube gives brilliant black sublimate near 
Uses . — Used in dyeing and calico-printing. When 



facture of chains and ornaments t the combination affording a brilliant polish. It is also alloyed with copper t many ornamental and 
in medicine. The ores were used to a greater extent formerly than now in the production of certain colors. 



Gives in closed tube 
metallic arsenic. 



Reacts for arsenic, sul- 
phur and iron. Soluble 
in nitric acid, with sep- 
aration of sulphur. 
In solution ammonia 
gives reddish -brown 
precipitate (ferric hy- 
drate). 

Soluble in aqua regia 
and caustic potash. 
HC1 precipitates from 

this latter solution 
lemon-yellow flocks. 



Tin-white, 


Metal- 


Tin- 


Vol. 


light to 


lic. 


white, 


with 


lead-gray, 




etc., , 


out . 


tarnishes 




like 


fu- 


grayish 




color. 


sion. 


black. 








Silver- white 


Metal- 


Gray- 


2 


to steel- 


lic. 


black. 




gray. 









35 



5<5 



5-7 



6.2 



III. 



IV. After. 



See under heading Arsenic, 
etc. 



See under heading Arsenic, 
etc. 



Fine golden 


Pearly, 


Paler 


or lemon- 


resin- 


yel- 


yellow. 


ous. 


low 

than 

color. 



Easily 1.5 



3.5 IV. 



See under heading Arsenic, 
etc. 



Name. 



Com p. and 
Percentage 
of Important 
Constituent. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



ABSEHIC AND ITS COMPO u xi jjS.— Continued. 

Realgar. AsS. Easily recognized by its color, etc. Sectlle, granular, compact or 

incrnstating. 
Arsenic, Often associated with orpiment and ores of silver, etc. 



On charcoal same as above. In closed 
tube melts, volatilizes, and makes a 
transparent red sublimate. In open 
tube when heated carefully yields 
white sublimate of arsenic tri- 
oxide. 



Asbestos 


(CaMgFe) 


(Moun- 


SiO.. 


tain 




Cork; 


Variable. 


Moun- 




tain 




Leather). 





Several varieties. Finely fibrous (amianthus) and fibres easily 
separable. Variety of hornblende (actinolite) or, commercially 
speaking, of serpentine. 

Chrysotile (commercial asbestos) is largely mined in the serpentine 
belt of Canada, Province of Quebec, where it is usually found 
filling small cracks or seams in the fractured serpentine. True 
asbestuty mineralogically considered, is of but small economic 
importance. 



Gives same reaction as hornblende, 
which see. 



90 



Characters. 

TeEATM BUT WITH ACIDS, ETC. 



Dissolves with difficul- 
ty in aqua regia, sul- 
phur being precipitat- 
ed. Boiled with caustic 
potash is decomposed, 
leaving a brown pow- 
der undissolved. 

The pure variety is 
distinguished from 
some varieties of fi- 
brous serpentine 
which much resemble 
it (e.g.. ckrysoti //.com- 
mercially sometimes 
known as bostonite) by 
yielding no water in 
closed tube and not 
being readily acted 
upon by acids. 

Chrysottle % or the as- 
bestos of commerce, 
affords much, water in 
closed tube. 



Colo*. 


Lustre. 


Streak 


Fusi- 
bility. 


Hard- 

NESS. 


Light or au- 


Resin- 


Au- 


Easily 


1.5-2 


rora-red, 


ous, 


rora- 






scarlet-red 


trans- 


red to 






to orange- 


lucent 


orange- 






yellow. 


to 

trans- 
parent. 


red. 






White, 


Fibrous, 


White, 


6. 


55 


greenish 


silky or 


slight- 


Around 


or 


white, 


satin- 


ly 


edges 


a. 5-4 


green, yel- 


like. 


shin- 


with 




low, brown- 




ing. 


diffi- 




ish. 






culty. 





Ckys- 
Sp. Gb. tall** 

CATION. 



3.5 



Magnetic 
before 

OR AFTER 

Heating. 



3-3 

or. 

2.5-2.6 



Besides being an ore of ar- 
senic, it is somewhat used 
in the manufacture of fire- 
works, especially for the 
production of what is known 
as White Indian Fire. 



It is largely used for fire-proof 
clothing (for which the fibres 
must be long), for the pack- 
ing of pistons and valves, for 
the covering of steam pipes 
and boilers, and in many oth- 
er cases where such fire-proof 
and non-conducting material 
as asbestos-cloth may be de- 
sirable. It is also used in 
making liquid and fire-proof 
paints, fire-proof cements, 
sheet and roll millboard and 
flooring, and in combination 
with hair-felts and other sub- 
stances. 



Namb. 



Barite 
(Heavy- 
spar; 
a Vein- 
stone). 



COMP. AMD 

Percentage 
op Important 
Constituent. 

BaSO«. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



Usually recognizable by its weight, and the fact that it decrepitates 
and colors the flame yellowish green when ignited in forceps. 
(See Flame Colors in Appendix.) 

Often found in connection with and as the gangue of many of the 
metallic ores, such as cobalt, lead, manganese, etc.; also with 
silver, copper, etc. Occurs throughout the Rocky Mountain 
region and Missouri and elsewhere — in New Jersey, North Caro- 
lina, Virginia, etc. It is rarely found in connection with gold 
ore, e.g., Huanaco, Chile. 



Distinguished from lead carbonate by 
the foregoing, and the fact that it 
yields on charcoal no metallic glob- 
ule, and does not react for lead. On 
charcoal reduced toa sulphide. With 
soda gives at first a clear pearl, but 
on continued blowing yields a he- 
patic mass, which spreads out and 
soaks into the coal. If a portion of 
this mass be removed, placed on a 
clean silver surface, and moistened, 
it gives a black spot of silver sul- 
phide. Should the barite contain 
calcium sulphate, this will not be 
absorbed by the coal when treated 
in powder with soda. (Dana.) 

BISMUTH A3TD ITS COMPOUNDS. 

Its presence is detected by characteristic lemon or orange sublimate, which it and its compounds give when treated alone or 
Readily dissolved by nitric acid, which solution, when concentrated, gives white precipitate when poured into excess of water. The 
metals, e.g., in the manufacture of pewter ers* solder, mosaic gold, etc; also used in the manufacture of type-metal and fusible metal. TAe 
colors, while the basic nitrate is used as a cosmetic and in medicine. The ores follow. 



Characters. 

Treatment with Acids, etc. 

With soda gives sul- 
phur reaction. Insol- 
uble in acids. 



Color. 


Lustre. 


Streak 


Fusi- 
bility. 


Hard 

NESS. 


Generally 


Vitre- 


Whit- 


3 


3 


whitish, but 


ous to 


ish. 






of alt colors 


resin- 








— yellow, 


ous; 








brown, blue, 


some- 








etc. 


times 
pearly 
trans- 
lucent. 









Sr. Gk. 



4-5 



Magnetic 
before 

,.~..n W OR AFTER 

ZATION. HlAT1NG , 



Crys- 

TAIXI* 



IV. 



Usjts. 



Used chiefly in the manufac- 
ture of pigments, as a cheap* 
er substitute for white lead, 
or in the adulteration of the 
latter. It is also used to a 
much smaller extent as a 
makeweight by paper manu- 
facturers, and in the prepara- 
tion of canvas covers, etc. 




with soda on charcoal before blowpipe in R. F. With sulphur and potassium iodide gives a scarlet coating far from the assay, 
ores are rare, the supply being furnished principally by the native metal. ' Uses. — Principally used as an alloy rtrith other 
sails are quite extensively employed for various purposes , the oxide with boric and silicic acids being used for optical glasses % for porcelain 



83 



Hamk. 



Com p. and 
Pbkcsntags 
or Important 
Constituent. 



General Chabactkbs and Associations. 



Specific 



BISMUTH. AND ITS COMPOUNDS.— Continued. 



Native. 



Bi. 



Bismuth 


BUS,. 


Glance 




(Bis- 


Bismuth, 


muthin- 


8l.2*. 


ite or 




Sulphide 




of Bis- 




muth). 





Brittle and somewhat malleable. Occurs in arborescent shapes; 
foliated and granular. Found usually in connection with ores 
of cobalt, nickel, silver, lead, and zinc, and sometimes iron; also 
in quartz with wolframite, scheelite, blende, and galena. 



Opaque, soft, and brittle. Fuses in flame of candle. Found in 
connection with tin, gold, and other metallic ores, such as pyrite, 
chalcopyrite, magnetite, limonite, etc.; also with garnet, barite, 
apatite, etc. 



Before Blowpipe. 



Fuses easily, with odorless fumes, and 
does not continue to burn after re- 
moval from the flame. The globule 
is brittle when cold, but somewhat 
malleable when heated. Volatilizes 
after long blowing, and imparts to the 
coal at first a white coating, which 
becomes partly yellow and partly 
orange. The color slightly fades on 
cooling and becomes lemon-yellow. 
In glass tube it yields scarcely any 
fumes, and the metal becomes sur- 
rounded with fused oxide of a dark- 
brown color, which changes to yellow 
on cooling. By this deportment it 
can be easily distinguished from na- 
tive antimony and tellurium. 

Fuses in R. F., with effervescence, 
giving a globule of bismuth and 
characteristic coating. In open 
tube sulphurous fumes and white 
sublimate which B. B. fuse into 
drops, brown when hot and yellow 
on cooling. 



84 



Characters. 



Treatment with Acide,btc. 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 



Sf.Ge. 



r«v*. Magnetic 
taiIT- «"°«« 
Heating. 



Uses 



In nitric acid soluble 
without difficulty. The 
concentrated solution 
yields a white precipi- 
tate on addition of 
much water. 



Reddish sil- 
ver-white. 
Subject to 
tarnish. 



Metal- 
lic. 



White 
like 
color. 



a.5 



97 



HI. 



See under heading Bismuth, 
etc. 



Soluble in nitric acid. 
Water added causes 
solution to become 
turbid, and finally 
yields a white precipi- 
tate of bismuth oxy- 
nitrate. 



Tin-white to 


Metal- 


Gray, 


lead-gray, 
sometimes 
yellowish 
white. 


lic. 


some- 
times 
with 
irides- 
cent 
tar- 
nish. 



6.5 



IV. 



See under heading Bismuth, 
etc. 



Name. 



Com*, and 

Pbkckmtage 
op Important 

'CONSTITUBNT. 



Spkcipic 



GwttAL Characters and Association*. 



Bbpobk Blowpipe. 



BlSMUTH AND ITS COMPOUNDS.— Continued. 



The other 
ores, 
which are 
rare, are: 
Bismuth 
Ochre. 



Tetrady- 



mite. 



Wittich- 
ite. 



Bis- 
mutite. 



Bi t O>. 

Bismuth, 
89.6*. 



An earthy oxide of bismuth. Massive and disseminated. Due On charcoal fuses and is easily re- 
usually to oxidation of the other ores. Iron and other impuri- duced to metallic bismuth, 
ties often present. Rare. 



Bi,(TeS).. 
Bismuth, 
59* 

CuaBiSa. 
Bismuth, 
43.1* 

SBi.CaOi* 

+oH.O.(?) 
Variable. 



Compound of bismuth and tellurium. Soils paper, 
ble. Almost always associated with gold ores. 



Cupreous bismuth. 



Laminae flexi- In open tube grayish-white sublimate which 
fuses to colorless drops B. B. On charcoal 
volatilizes and tinges flame bluish green. 

On charcoal fuses, throwing out 
sparks; residue treated with soda in 
R. F. yields a globule of copper. 

A hydrated carbonate of bismuth; another product of atmospheric Easily reducible to metallic state and 
action upon native bismuth. In incrustations, often earthy or gives yellow coating on coal. In 
pulverulent. Variable in composition. closed tube decrepitates and gives 

off water. 



Borax 
(Borate 
of Soda). 



Na,B«Ot 
+ 10H.O. 

Boron tri- 
oxide 

= 36.6* 
Soda 

= 16.2*. 



Taste slightly alkaline and sweetish. Soluble in water. Con- 
choidal fracture. Translucent to opaque. Most abundant in 
India and Thibet, where it is called Tinea/. Also quite abun- 
dantly found in the Tuscan lagoons and in California, Borax 
Lake, etc. 



Bubbles, swells up, and fuses to clear 
bead. Fused with fluor-spar and 
bisulphate of potassium colors flame 
around assay clear green. This 
reaction is best performed on plati- 
num wire. 



Characters. 



Treatment with Acids, etc. 



Soluble in nitric acid. 



Soluble in nitric acid 
with separation of sul- 
phur if present. 

Soluble in HC1 with 
evolution of hydrogen 
sulphide. 

Dissolves with effer- 
vescence in HC1; does 
not gelatinize, but af- 
fords a deep-yellow 
solution. 

Reaction alkaline. 
Treated with acids it 
does not effervesce. 
Moistened with strong 
sulphuric acid gives 
green flame. Boiling 
water dissolves double 
its weight of this salt. 



Color. 


Lustre. 


Streak 


Fusi- 
bility. 


Hard- 
ness. 


St. Ge. 


r»«« Magnetic 
i-'TT BEFORE 
TALLi- __ _„ , _- 
..•*.Am* OR AFTER 

zation. heating. 


Yellowish to 
grayish 
white, rare- 
ly verging 
on apple- 
green. 


Ada- 
mantine 
to dull. 


Dull 

white, 

earthy 


Easily 


I 


4-3 


ivr 


Pale steel- 
gray. 


Splen- 
dent, 
metallic. 


Like 
color. 


Easily 


i.5-a 


7.5 


in. 


Steel-gray. 


Metal- 
lic. 


Black 


Easily 


3-5 


4-5 


IV. 


White, gray- 
ish to yel- 
low. 


Dull but 
vitre- 
ous 
when 
pure. 


Green- 
ish • 
gray 
to col- 
orless. 


Easily 


4-4.5 


7 


Amor- 
phous 


White, gray- 
ish, bluish, 
and green- 


Vitre- 
ous, 
resin- 
ous, or 
earthy. 


White 


Easily 


2-2.5 


1.72 


V. 


ish. 


welding 
glazing, 


and soldering, 
and in the ma 



Use 



See under heading Bismuth, 
etc. 



See under heading Bismuth, 
etc. * s 



See under heading Bismuth, 
etc. 



See under heading Bismuth, 
etc. 



It is used chiefly as a flux in 
analytical and metallurgical 
operations, as an aid in 
in enamelling and pottery- 
manufacture of glass and arti- 
ficial gems. It is also used in medicine, and quite large- 
ly by meat-packers'and others as an antiseptic. It has a 
number of other uses in the various industries. 



37 



Name. 



COMP. AND 

Percentage 
op Important 
Constituent. 



Specific 



General Characters and Associations. 



Before Blowpipe* 



CALCIUM AND ITS COMPOUNDS. 

The presence of calcium may be often detected by the fine orange-red color which its compounds impart to blowpipe 
precipitate (CaCO») which is soluble in acids, with effervescence (CO,). N 



Calcite. 


CaCd. 


(Calc 




Spar) 


Calcium 


(a Vein- 


carbonate 


stone, 


= ioo or 


etc.). 


Lime = 


Many 


56*, etc. 


varie- 




ties. 





lime- 


Generally 


stones 


more or 


(mas- 


less im- 


sive). 


pure. 



Infusible. Held in forceps and moist- 
ened with HC1 gives yellowish-red 
or orange color to flame. 



Usually shows distinct rhombohedral cleavage. Easily scratched 

with knife. When deposited from calcareous springs (usually 

hot) or streams, or in caverns, called variously calcareous sinter, 

travertine, stalactites, stalagmites, Mexican onyx, etc., in which 

the peculiar and often beautiful banded appearance is due to the 

edges of the layers of deposition. 
Found in seams and veins in the many kinds of rock containing 

lime, and especially in or in close proximity to limestone strata. 

It is usually a secondary deposit derived from the dissolving out 

of the lime from the rocks in or near which it is found, often in 

veins in connection with and as the gangue of many of the 

metallic ores. Very common. 

All common limestones and marbles are essentially only massive calcite or dolomite, usually more or less 
(See also Flame Colors in Appendix.) 



86 



CHARACTER*. 

TUAXMIKT WITH ACIDS, ETC. 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 
ness, 



Sp. Gx. 



Magnetic 
before 

• a -maw 0R AFTER 

NATION. Heatxnc . 



Crvs- 

TALLI- 



UsES. 



flame. Best, however, to test for it in the liquid way. Carbonate of ammonium produces in neutral calcium solutions a white 



Soluble in cold dilute 
HO, with efferves- 
cence. The dilute so- 
lution gives no pre- 
cipitate with sulphuric 
acid, but the strong 
solution does. 



Colorless, 


Vitre- 


White 


white, and 


ous to 


or 


of all tints. 


earthy. 


gray- 




Trans- 


ish. 




parent 






to 






opaque. 





Infus 3 2.7 IH« One of the principal uses of calcite 

and of the purer grades of lime- 
stone is as a flux in blast-furnaces 
and for metallurgical operations. 
Compact limestone is very large- 
ly used as a building-stone, and 
marble (crystalline limestone) is 
largely employed for the same 
purposes, as well as for monu- 
mental, sculptural, and ornamen- 
tal purposes. The clayey as well 
as the pure varieties are largely 
used in the manufacture of ce- 
ments. It is also used in making 
glass if not containing too much 
impure from presence of clay or sands. For the different varieties see pp. 266-268, Dana's Mln. iron or other metallic oxides which 

color the glass. Limestone is the 
i. best and cheapest stone for rail- 
way ballast and macadamizing. Used extensively 
for curbstones, in bridge-building, etc., etc. Large 
quantities (usually scrap-marble) are used in the 
manufacture of carbonic acid gas for the many 
purposes for which this gas is employed, and 
when calcined it is largely used in making mor- 
tar, chloride of lime, and as a fertilizer. Very 
fine-grained and compact limestone is employed 
as a lithographic stone, but beds of limestone 
affording good lithographic stones are very rare. 
The uses of limestone are much more varied 
than those of any other rock. 

89 



Name. 



Coup. Artb 
percentage 
op Important 
Constituent. 



General Characters and Associations. 



CALCIUM AND ITS COMPOUNDS.-Ctontinued. 

Dolomite (CaMg) Common magnesian limestone. Generally very impure. Distin- 

(mas- COj. guished from common limestone by no effervescence with dilute 

sive). cold HO, or only very feeble. Much " hydraulic " limestone 

Calcium (so called from the fact that it sets after ignition and becomes 

carbonate solid under water), used in making cements, is here included. 

= 54«35- Frequently associated with serpentine and other magnesian rocks, 

Magnesium and with ordinary limestones. Often forms massive and exten- 

carbonate sive strata. Sometimes associated with gypsum, rock-salt, and 

= 45«°5. other results of the evaporation of saturated saline waters. 
etc. 



Specific 



Before Blowpipe. 



Harder than calcite, but sometimes 
chemical analysis required to dis- 
tinguish between the two. After 
ignition reaction alkaline. 



Gypsum CaSO* Scratched by the nail. Hydrous calcium sulphate. This when 

(mas- + 2H1O. compact is so-called alabaster, or when burned plaster of Paris, 

sive). Frequently associated with beds of rock salt, caliche (Chile salt- 

peter), etc. Also associated with pyrite, sulphur, etc. It is 
often produced where the decomposition of pyrites has an 
opportunity to affect adjacent limestone. Also associated with 
dolomite and anhydrite. 



Becomes instantly white and opaque, 
and exfoliates, then fuses to a glob- 
ule, having an alkaline reaction. 
When ignited at a temperature not 
exceeding 260° it again combines 
with water and becomes firmly 
solid. Gives sulphur reaction with 
soda in R. F. 



40 



Chakactbks. 
Trkatmbntwttm Acms, rrc 



COLOB. 



Lusnts. Streak 



FUSI- 
BILITY. 



Habd- 



Sp. Gb. 



Crys- 

. TALLI- 
ZATION. 



Magnetic 

BEFORE 
OR AFTER 

Heating. 



Usbs. 



effervesces in hot but 
not in cold hydrochlo- 
ric acid. Concentrated 
solution gives with 
sulphuric acid a pre- 
cipitate of sulphate of 
lime. 



In closed tube gives 
much water and be- 
comes opaque. Dis- 
solves quietly in much 
HO, and the solution 
gives a heavy precipi- 
tate with barium chlo- 
ride. Soluble in 400 to 
500 parts of water. 



White, gray, 
brown, etc. 



Vitre- 
ons to 
pearly 
to dull. 



Whit- 
ish. 



Infus. 3.5-4 3.8 



III. 



Colorless to 
gray dirty- 
white, and 
various 
shades. 



Pearly, 
silky, 
vitre- 
ous. 
Some- 
times 
dull, 
earthy. 



White 3.5 



3.3 



V. 



Many of the massive kinds af- 
ford good hydraulic lime, and 
when of the proper color are 
sometimes used as marble for 
architectural and ornamental 
purposes. It is largely used 
as a building-stone. Often 
used for the bricks employed 
in the manufacture of steel 
by what is known as the 
44 Basic " process. (See mag- 
nesium , etc.) 

One of the principal uses is in 
making plaster of Paris and 
for the manufacture of arti- 
ficial marble. It is also used 
as a fertilizer or land-plaster, 
and when pure in its natural 
state it is carved into orna- 
mental objects. It is used also 
in making certain cements. 



Name. 



COMP. AND 

Percentage 
op Important 
Constituent. 



Gbnbxal Characters and ASSOCIATIONS.- 



CALCIUM AND ITS COMPOUNDS.— Continued. 



Anhydrite 
(Variety 
"Flos- 
Ferri" or 
"Flower 
of Iron") 



Specific 



Before Blowpipe. 



CaS0 4 . It is an anhydrous calcium sulphate; fibrous and lamellar; often 

contorted; coarse and fine granular and compact. (Compare 
gypsum.) Found very often with rock-salt and gypsum, into 
which it often passes by absorption of moisture. Sometimes 
forms extensive beds. 



Reactions same as those of gypsum. 
Cleaves easily in three directions 
into square blocks. 



Aragon- CaCO,. 
ite. 



Much resembles calcite, but is not cleavable parallel to rhombo- 
hedron; also distinguished from it by its higher specific gravity 
and crystalline form. Transparent to translucent. 

Often found in connection with iron ores and in basalt and trap- 
rocks. Sometimes associated with copper and iron pyrites, 
galena, malachite, etc. 



Falls to powder, in which it differs 
from calcite. When containing 
strontium imparts more of a scarlet 
color to flame. 



Celestite. SrSQ 4 . 



Strontium, 
47.6*. 



Differs from baryta in the bright-red color of flame (strontium). 
(See Flame Colors in Appendix.) 

Usually found in the older formations, in sandstones and espe- 
cially in limestones. It is commonly associated with gypsum, 
rock-salt, and sulphur. Occasionally in connection with some of 
the metallic ores such as galena and sphalerite. 



With soda in R. F. gives a sulphur 
reaction. Frequently decrepitates 
coloring flame red. 



42 



Characters. 



TrBATMINT WITH ACIDS,RTC. 



Same as with gypsum, 
except in closed tube it 
gives no water. Is not 
precipitated by bi- 
chloride of platinum; 
insoluble in water. 



Behavior with acids 
same as for calcite, 
which it much resem- 
bles, but from which it 
is further distinguish- 
ed by different crystal- 
line form, absence of 
rhombohedral cleav- 
age, and higher spe- 
cific gravity. 



Very little acted on by Colorless, Vitreous, 
HC1, or HNO t . white, blu- pearly. 

ish,and>ed- Trans- 
dish, parent 
to sub- 
trans 
lucent. 



Color. 


Lustre. 


Streak 


Fusi- 
bility. 


Hard- 
mess. 


Sr. Gr. 


Crys- 
talli- 
zation. 


Magnetic 

before 

or after 

Heating. 


White, or 
tinged with 
gray, red, or 
blue. 


More or 
less 
pearly, 
or vit- 
reous, 
trans- 
parent 
to sub- 
trans- 
lucent. 


Gray- 
ish 
white. 


2-3 


3-3-5 


a. 95 


IV. 




Colorless; 
white, with 
light tinges 
of gray, yel- 
low, green, 
and violet. 


Vitre- 
ous to 
resin- 
ous on 
broken 
sur- 
face. 


Un- 
colored 


Infus. 


3.5-4 


2.9-3 


IV. 





White 



3-3.5 



39 



IV. 



Uses. 



A scaly variety containing a 
small amount of silica, and 
known as vulpinite, is some- 
times cut and polished for 
ornamental purposes. 



May possibly be used for 
some of the same purposes 
as calcite, but of small im- 
portance in the arts. 



Its principal use is for mak- 
ing nitrate of strontia which 
Is largely employed in pro- 
ducing a red color in fire- 
works. 



at 



Name. 



Com p. and 
Percentage 
of Important 
Constituent. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



CHLOBINE. 

This element, though not occurring in a free state in nature, is largely used and frequently met with through the many 
Chlorides when heated with strong sulphuric acid, save those of mercury, silver, and tin, evolve hydrochloric acid gas, 
off, recognizable by its irritant odor, green color, power of bleaching litmus, etc., and by the purple stain it produces on a piece of 
furnish a mass which when warmed with strong sulphuric acid gives off deep-red vapors of chromic chloride, CrOCU, decomposable 
rendered ammoniacal. (Odling.) Fused in a bead of microcosmic salt saturated with CuO imparts an azure-blue color to 
chemistry, in the manufacture of chloride of lime, chloride of potassium, etc. Chloride of lime is largely used as a disinfectant and 
liberated. Chlorine is one of the best disinfectants or deodorizers known, or furnishes the basis for them. It is also quite largely used in 

CHROMIUM AND ITS COMPOUNDS. 

Exists chiefly in two native compounds, viz., crocoite (Siberia) or chromate of lead, and chromite or oxide of chromium and 
slightly magnetic. Fuses slightly, is soluble, and imparts a beautiful emerald-green color to beads of borax and salt of phos- 
(the chrome-yellow of commerce). Bichromate of potash (which is the salt from which all the others are obtained) is quite extensively 
of very hard grades of steel known as chrome steel. 



Chromite FeCr,0 4 . In many varieties quite strongly magnetic; in others, only very 
(Chromic feebly. Usually found associated with serpentine (altered peri- 

Iron). Chromium dotite) in which it forms irregular embedded masses or veins. 

Sesqui- * Sometimes found associated with gold, pyrite, galena, quartz, 
oxide, 68*. etc. Commercially speaking, the only ore. 



In O. F. infusible. In R. F. becomes 
slightly rounded on edges and be- 
comes more magnetic. Best test is 
that it imparts a beautiful charac- 
teristic emerald-green color to beads 
of borax and salt of phosphorus 
when cold. This color is heightened 
by fusion on charcoal with metallic 
tin. 



H 



Characters. 



Treatment with Acids, etc. 



Color. 



Lustre. Streak 



Ptisi- 

BIMTV. 



HARD- 
NESS. 



Sp. Gr. 



Magnetic 

BEFORE 
,^,„„ OR AFTER 

ZATION. HeaTINC> 



CrYS- 

TALU- 



TJSHS. 



compounds which it forms, such as chloride of ammonium, copper, mercury, potassium, sodium, tin, silver, etc., which see, 
known by its pungent smell and acid reaction. When heated with peroxide of manganese and sulphuric acid, chlorine gas is given 
starch-paper moistened with iodide of potassium* When fused with a little carbonate of sodium and red chromate of potassium, they 

flame. Uses. — Common salt {chloride of sodium) is the form in which chlorine is most frequently met with. It is, however \ used in 

deodorizer. Much the same results have been lately obtained by passing a current of electricity through sea-water t free chlorine being thus 
the recovery of gold from its ores by what is known as the " chlorinalion " process. 

Iron. It is, when reduced to metallic state, a whitish, brittle, and very infusible metal. Chief source is chromite, which is 
phorus when cold. ■ Uses. — Its compounds are used in imparting a green color to glass and in the production of chromate of lead 

employed in calico-printing. It also has various other uses. An increasing quantity of chrome-iron ore is being used in the manufacture 



Only slightly attacked 
by HC1, but soluble 
by fusion in bisul- 
phate of potash or 
soda. 



Iron-black, 


Sub- 


Yel- 


pitch-black 


metallic 


low- 


to brown- 


to me- 


ish 


black. 


tallic. 


brown 
to 

dark 
brown 



Infus. 5.5 



43 



Both. 
Some- 
times 
but 
slightly. 



See under heading Chromi- 
um, etc. 



4S 



Kamb. 



Coup. and 
Pbrcbntagb 
of Important 
constxtubmt. 



&BNBXAL ChaKACTBRS AllD ASSOCIATIONS. 



Specific 



Bbfov Blowfifb. 



CHBOMIUM AND ITS COMPOUNDS.— Continued. 



Chro- 
mate of 
Lead 
(Croco- 
ite). 
Very 
rare. 



Pb0 4 Cr. 

Chromium 
trioxide, 



This is chiefly manufactured from above, and is known as the 
" chrome- yellow " of the painter. Occurs very rarely in nature 
in metamorphic rocks (gneiss or granite), associated with gold, 
pyrites, galena, quartz, etc. 



Blackens and fuses and forms a shin- 
ing slag containing globules of lead. 
Gives emerald-green bead in both 
flames. 



COALS. 

These may be generally easily recognized by their physical characters, which are too well known to require description. <( It 
bituminous matter to anthracite, and further to kinds which approach graphite." Each species gives variable analyses according 

Note. — A coking coal is a bituminous coal which softens or becomes pasty or semi-viscid in the fire. This is attended with 
or less coherent grayish-black cellular or fritted mass is left, which is coke, or the part not volatile, and which varies from 50-851% 
in general composition, but it burns freely without softening or any appearance of incipient fusion. The " coke" resulting from 



Anthra- C (80-95 Does not take fire in lamp-flame. Hard as compared with other 

cite. p. c). varieties of coal, lustrous, and breaks with conchoidal fracture. 

Burns with a feeble flame of a pale color. 



In closed tube yields a little water 
and very little tarry product (bitu- 
men). B. B. burns with feeble flame, 
is slowly consumed, and leaves but 
little ash. 



46 



Characters. 



TREATMENT WITH ACIDS.ETC. 



Color. 



Reacts for lead and Bright red 
chromium. or hyacinth- 

red. 



LUSTRE. 


Streak 


Fusi- 
bility. 


Harp- 

NESS. 


Trans- 


Orange 


1.5 


2.5-3 


lucent 


yel- 






and 


low to 






vitre,- 


orange 






ous. 








Ada- 








mantine 









Sr. Ok. 



Crys- 

: TALU- 
ZATION. 



Magnetic 

BEKORB 
OR AFTER 
H BATING. 



Uses. 



passes from forms which still retain the original structure of the wood (peat, lignite) and through those with less of volatile or 
to amount of impurities present. 

escape of bubbles of gas* The volatile products resulting from the decomposition of the softened mass being driven off, a more 
A non-coking, free-burning coal may be like the farmer in all external characteristics and even in percentage of volatile matter and 
this is not a proper coke, being often in a powder or in the form of the original coal. (Dana.) 



Boiled in solution of Black, 
potassa it gives no 
color to liquid. 



Brilliant Black 


With 


and lus- 


some 


trous. 


diffi- 


Subme- 


culty. 


tallic 




iron 




black 




and of- 




ten iri- 




descent* 





2-2.5 



1.5 



Very extensively used as a 
fuel where great heat and a 
smokeless fire are desirable; 
also usually admixed with 
coke for iron-smelting, as in 
Pennsylvania and to a less 
extent in New South Wales. 



Name. 



COMP. AND 

Percentage 
dp Important 
Constituent. 



Specific 



Gbmbbal CMAJUcras AMD Associations. 



Bepoke Blowpipe, 



COALS.— Continued. 

Semi- This is the commercial name of the variety which Is intermediate between anthracite and the following, i.e., in being 

bitumi- which yield upon analysis, for example, fixed carbon, 70-85*. (Pocahontas Flat-Top Semi-Bituminous.) 

nous. 



Bitu- 


50-85 p. c. 


minous 


residue on 


Coal 


being 


(coking 


strongly 


and non- 


heated. 


coking 




varie- 




ties). 





Burns with bright-yellow smoky flame in the fire, often with elimi- 
nation of bituminous odor ; frequently breaks into cubes. Upon 
distillation gives out hydrocarbon oils or tar, hence name bitu- 
minous. Usually a firm compact texture, but fragile as compared 
with anthracite. 



Burns and leaves comparatively little 
ash, which varies with the amount 
of silica, oxide of iron, clay, etc., 
present as impurities in the coal. 



Lignite Very vari- 
or Brown able. 
Coal 
(often 
black). 



Air-dried lignite contains frequently 15-20* or more of water, which it loses when dried at no* C. or 230* F. 
Very abundant; often impure; not suitable for making commercial coke, or very rarely, and affording 
large proportion of volatile matter. Variety, Jet. 



Cannel A variety of bituminous coal, which differs from the purer varieties in often containing much more extraneous 

Coal. causes it to be much used in enriching gas coals. It is very dense and compact, brown or black in color. Dull 

splits and crackles or "chatters" without melting; like asphaltum. Burns readily with bright flame. Leaves ash 

a large proportion of burning or lubricating oils, much larger than bituminous coal. Graduates into oil-producing. 

The variety/// (see above) which is used for ornament and jewelry resembles cannel coal, but is harder, of ft 

land), in the manufacture of gas or in enrichingother gas coals. 



48 



Characters. 

Treatment with Acids, etc 



Fust- Habd- 



Crys- 



Magnbtic 



Color. Lustre. Streak *?zZ ~»«. Sr. Gr talli- __ . _.__ 

BILITY. NESS. •a-mom OR AFTER 

XATION. Hbatinc . 



Use*. 



less hard than anthracite and containing more volatile matter. Some of the Virginia coats furnish good examples, such as those 



When heated in flask Black. 
or closed tube yields 
brown and brownish- 
yellow tar drops or oil. 
Imparts but little color 
to potash solution upon 
boiling. The powder 
boiled with ether im- 
parts scarcely any 
color. 



Gives a brown color to Brown, 
liquid when boiled in brown- 
solution of potassa. black to 
black. 



Black, 
resin- 


Black. 
Some- 


ous. 
Some- 
times 
pitchy 
or 


times 
choc- 
olate, 
col- 
ored. 


greasy. 





Easily 1.5-2 



Dull 
and 

slightly 
resin- 


Brown, 
black- 
ish to 
black. 


ous. 





1.14- 

1.40 



Easily 1.5-2 1.13 



The most common fuel for 
producing power and heat. 
The following coals are em- 
ployed for the same purposes. 
Large quantities of bitumi- 
nous coal are converted into 
co&e for use in blast-furnaces, 
smelting plants, and in many 
other manufacturing indus- 
tries, as well as for domestic 
use. 



earthy matter, and usually in containing much greater percentage of volatile bituminous substances (hydrocarbons), which fact 
earthy to brilliant waxy lustre. Not easily frangible, and breaks with uneven of largely conchoidal fracture. When burning it 
ranging from 3* to 20*. Hard enough to take a polish. Affords on distillation, after drying, 40-66* of volatile matter, including 
coaly shales, 
deeper black and higher lustre, and takes a more brilliant polish* Uses. — Used quite largely, as are certain coaly shales (Scot- 



Name. 



Com p. and 
Percentage 
of Important 
Constituent. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



COBALT AND ITS COMPOUNDS. 

Easily recognized by the characteristic deep sapphire-blue bead in both flames with borax or salt of phosphorus. The 
insolubility of the black sulphides of nickel and cobalt in dilute HC1 suffices to separate these metals from the remaining members 
If ferrid-cyanide be added, the precipitate is brown-red. (Do not confound with similar precipitate of copper.) Sometimes 

suffices to readily distinguish the following ores from arsenopyrite. Uses . — The principal use is in the preparation of colors. 

manufacture ; for enameling and tinting writing-paper, etc. The smalts and azures of commerce are prepared by fluxing glass with 



Smaltite 
(Nickel 
variety, 
Chlo- 
anthite), 
Speiss 
Cobalt. 



CoAsj or 
(CoFeNi)As, 

Very varia- 
able. 



Chief ore of cobalt. On charcoal B. B. affords garlic odor of 
arsenic; fuses to magnetic globule, which with fluxes gives indi- 
cations of Fe, Co, and Ni. In closed and open tube indicates 
presence of arsenic. (See Nickel ores.) 

This and the other ores of cobalt are usually associated with ores 
of nickel, and sometimes with those of silver, lead, and copper. 
Sometimes found alloyed in small quantities with nickel in many 
meteoric irons. 



To borax bead imparts intense sap- 
phire-blue color in both flames. 
Should be first roasted. Presence 
of large amounts of ircn colors 
bead green. 



Cobalt 
Glance 
(Cobalt- 
ite). 



CoAsS. 

Cobalt, 

35-5* 



Next in importance to above. 
Cubical crystals, brittle. 



Reaction for cobalt same as above. 



Presence of cobalt easily recognized 
as above. 



50 



Characters. 



Treatment with Acids, etc. 



Color, 



Lustre. Streak 



Fusi- 
bility. 



Hard- 
ness. 



Sp. Gr. 



Crys- 
talli- 
zation. 



Magnetic 
before 

OR AFTER 

Heating. 



Uses. 



sulphurcts should be roasted on charcoal before testing with borax, as in other metallic species. Dissolves in nitric acid. The 
of the group. If ferrocyanide of potassium be added to solution first made freely ammoniacal, a green precipitate is produced, 
associated with oxides of manganese. (Missouri and South Carolina.) Largely associated with arsenic, but the blue color of bead 
The protoxide has an intense coloring power when vitrified* and forms the basis of alt the blue colors used in glass and porcelain 
protoxide of cobalt. These are also sometimes produced by fusing the protoxide with pure quartz-sand or carbonate of potassium. 



Gives metallic arsenic 
in closed tube. Con- 
centrated HNO« dis- 
solves with separation 
of arsenious acid, and 
the solution has gener- 
ally a rose-red color. 
Yields with silicate of 
potassaablue precipi- 
tate; with chloride of 
barium added to solu- 
tion, no precipitate. 

Gives no arsenic in 
closed tube, but in open 
tube yieldssulphurous 
fumesand arsenic sub- 
limate. With chloride 
of barium added to 
dilute nitric solution 
gives a heavy deposit 
of BaSO<. 



Tin-white to 
steel-gray, 
occasion- 
ally irides- 
cent or 
grayish 
from 
tarnish. 



Silver-white, 
inclining to 
red. Also 
grayish 
black. 



Metal- 
lic. 



Gray- 
black. 



Easily 5.5-6 



6.8 



I. 



Slightly 
after. 



See under heading Cobalt, 
etc. 



Metal- 
lic. 



Gray- 
black. 



Easily 



5.5 



See under heading Cobalt 
etc. 



51 



Name. 



Com p. and 
percentage 
ok Important 
Constituent. 



Gbwsral Characters and Associations. 



"COBALT AMD ITS COMPOUNDS.— Continued. 



Cobalt 
Bloom 
(Ery- 
thrite; 
Peach 
blossom 
Ore). 



COaOkAfti 

+ 8H a O. 

Cobalt, 

295*. 



Reaction same as above. Possesses foliated structure like mica. 
Hydrous Cobalt arsenate. 



Specific 



Before Blowpipe. 



Arsenical fumes, and fuses to blue 
glass, etc. In closed tube yields 
water at gentle heat and turns blu- 
ish. 



Earthy 
Cobalt 
(Asbo- 
lite). 



Cobalt 
Pyrites 
(Lin- 
naeite). 



MnO.CoO 
CuOH a O. 

Variable. 



(CoNi)«S« 
or Co»S 4 = 
Cobalt, 

57-9*. 
Variable 
quantities 
of nickel 
and iron 
often re- 
place some 
of the 
cobalt. 



Earthy variety, sometimes associated with bog manganese (wad). 
Uncommon. 



Generally found impure, i.e., admixed with nickel, iron, and 

arsenic. 
Found sometimes in metamorphic rocks in association with chal- 

copyrite, bornite, sphalerite, pyrites, etc. 



With soda on platinum wire or foil 
gives manganese reaction (green); 
but with borax or salt of phosphorus 
gives a deep blue bead. With tin 
on charcoal in R. F. sometimes me- 
tallic copper. 

Roasted mineral gives borax bead 
sapphire-blue color, and reacts usu- 
ally for cobalt, nickel, and iron, and 
sometimes for arsenic. 



52 



Characters. 



Treatment with Acids, etc 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 

NfeSS. 



Sp. Gx. 



Crys- 
talli- 
zation. 



Magnetic 

before 

or after 

H BATING* 



Uses. 



In HC1 readily dis- 
solves to rose- red so- 
lution. When concen- 
trated appears blue 
while hot. 



Soluble in HC1, with 
evolution of chlorine. 
Solution usually blue, 
turning rose-red on 
addition of water. 



Crimson to Pearly 

peach-red adaman* 

to greenish tine to 

gray. dull. 



Black. 



Dull. 



Paler 2 

than 
color, 
dry 
pow- 
der 
laven- 
der- 
blue. 

Earthy Some 
varie- 
ties 
fuse. 



2 3.9 



See under heading Cobalt, 
etc. 



2.25 3.1 



See under heading Cobalt, 
etc. 



Soluble in HNO,, form- 
ing rose-red solution. 



Pale steel- 
gray, tar- 
nishing 
copper-red. 



Metal- 
lic. 



Black- 
gray. 



Easily 5.5 



4-9 



See under heading Cobalt, 
etc. 



53 



Name. 



COMP. AND 

Percentage 
op Important 
Constituent. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



COFFEB AND ITS COMPOUNDS. 

Borax bead in O. F. is green when hot, and greenish blue when cold; in R. F. colorless, if saturation be weak, but red with 
obtained. When combined with the oxides, tin and borax should be used. When ammonia in excess is added to nitric acid 
roasted before making B. B. test with borax. For traces of copper place drop of suspected solution on platinum-foil; place in 
with a drop of HC1 and ignited B. B. color the flame azure-blue.— — Uses. — Copper is largely employed in the manufacture of many 
other purposes. Electrical inventions consume large and, with the advance of the science, constantly increasing quantities of this metal, 
also used very largely in many important alloys; e.g., with zinc it constitutes brass, and with tin it forms bell-metal and bronze. It is to 

Native. Cu. Ductile and malleable. Readily recognized. Rapidly oxidizes su- Fuses readily, covered with black 

perficially to greenish rust upon exposure (Cu»(OH)»CO»). Lake oxide (CuO). Moistened with HC1 
Superior most important region, where it occurs in conglomerate, turns flame sky-blue, 
sandstone, and trap rocks. Often results from oxidation of 
other copper ores, and found in association with them. 



Copper 
Pyrites 
(Chal- 
copyrite) 



Chalco- 
cite 

(Copper 
Glance 
or Black 
sulphide 
of copper). 



CuFeS,. 

Copper, 

34-5*. 



Cu s S. 

Copper, 

79-8* 



Readily distinguished from gold and iron pyrites. Fracture 
uneven, brittle. Often contains a large quantity of pyrite. 



Somewhat resembles argentite, but is not sectile, and affords dif- 
ferent results B.B. Solution in HNO» covers knife-blade with 
copper, but similar solution of the silver ore covers copper-plate 
with silver. This and the following ores, except tetrahedrite, are 
usually alteration-products of original copper pyrites. 



Fuses to steel-gray brittle globule, 
which is magnetic; with soda the 
roasted mineral gives a globule of 
copper containing iron. Gives sul- 
phur fumes on coal. Blue flame 
with HC1. 

Alone or on coal the fine powder 
yields a globule of copper after 
sulphur is driven off. Sometimes 
contains very smal 1 quantities of 
iron or silver. 



54 



Characters. 



Treatment with Acids, rtc. 



Color. 



LUSTRS. StRSAIC 



Fusi- 
bility. 



Hard- 
ness. 



Sp. Gr. 



Crys- 
talli- 
zation. 



Magnetic 

BEFORE 
OR AFTER 

Heating. 



Uses. 



strong saturation when hot; metallic copper and copper- red when cold. On charcoal with soda, a copper-colored globule is 
solution, the liquid is colored blue; metallic copper is deposited on iron wire or a nail immersed in this. .Specimens should be 
this a piece of zinc; a film of copper will be deposited on the platinum-foil at point of contact. Copper compounds moistened 
kinds of utensils, in the manufacture of wire and plates for engraving, etc, for sheathing ships, for coinage, and for a vast number oj 
Wire made from this metal is more suitable for conducting the electrical current than wire made from any other metal except silver. It is 
a certain extent used in the formation of blue and green pigments. 



Excess of ammonia to 


Copper-red. 


Metal- 


Cop- 


3. or 


nitric acid solution 




lic. 


per- 


78o°C. 


renders liquid sky- 






red. 




blue in color. Same 










applies to various ores 










of copper. 










Dissolves in HNO», 


Brass-yel- 


Shining 


Green- 


2 


with separation of sul- 


low, tar- 


metal- 


black. 




phur forming green 


nishes, 


lic. 






solution. Reacts for 


sometimes 








sulphur, copper, and 


iridescent. 








iron* 










Dissolves in hot HNO3, 


Blackish 


Metal- 


Black- 


Easil) 


with residue of sul- 


lead -gray. 


lic,dull. 


ish 




phur. 


Often tar- 
nished blue 
or green. 




lead- 
gray* 
some- 
times 
shining 





3.5-4 



2.5-3 



8.9 



4.3 



5.5 



II. After. 



IV. 



See under heading Copper, 
etc. 



See under heading Copper, 
etc. 



See under heading Copper, 
etc. 



55 



INamb. 



Co**. AND 

percentage 
op Important 
constitubmt. 



Specific 



GkNEBAL ChAEACTEES AMD ASSOCIATION*. 



COPPEB AND ITS COMPOUNDS.— Continued. 



CusFeS.. 

Copper, 
$5-5*. 



Bornite 
(Varie- 
gated 
Copper 
Pyrites 
or Eru- 
bescite; 
Peacock 
Ore). 



Mala- 
chite 
(Copper 
Car- Copper, 

bonate). 57-3* 



2CuO,CO, t 
H.O. 



Bepoke Blowpipe. 



Distinguished from chalcopyrite by its pale reddish-yellow color, 
and its rapidly tarnishing to bluish and reddish shades of colors. 
Sometimes admixed with copper glance, when it yields 50-70* 
of copper. 



Readily distinguished by green color. Fibrous cleavage. Com- 
mon with other ores of copper, resulting from their alteration. 



Fuses in R. F. to brittle gray globule 
attracted by magnet. Minute 
specks from crushed globule will, 
with borax bead, give copper re- 
action. 



Decrepitates and blackens. Colors 
the flame green. With borax fuses 
to deep green globule. Ultimately 
affords bead of copper in R. F. 



Azurite 


3CuO, 


(Blue 


2CO,H,0. 


Mala- 




chite). 


Copper, 




55.1*. 



As above. Color blue. Common with other ores, etc. Usually Similar to above, 
accompanying other copper ores, especially malachite and 
cuprite. 



66 



Characters. 

tsbatm but with acids,btc« 



Dissolves with separa- 
tion of sulphur. Part- 
ly soluble in HNO,, 
when it reacts as 
above. 



Gives much water in 
closed tube. Dis- 
solves completely, 
with effervescence, 
in HNOi, giving off 
CO«. This distin- 
guishes it from all 
other green ores ex- 
cept emerald nickel, 
q. v. 

As above. 



COLOR. 


i Lustre. 


Streak 


| Fusi- 

' BIL1TY. 


HARD- 
NESS. 


$ronze - yel- 


Metal- 


Pale 


Easily 


3 


low, purple 


lic. 


gray- 






on exposed 




ish 






ledges; also 




black, 






copper - red 




i slight- 






to brown. 




ly 

shin- 
ing. 






^rass to 


Silky to 


Paler 


2 


3-5-4 


emerald- 


dull, 


than 






green. 


earthy. 


color. 







Sp. Gr. 



. Crts- 

I TA14J- 
ZATION. 



Magnetic 

BEFORE 
ORAFTBR 

Heating. 



After. 



Nearly 
opaque. 
Crystals 
translu- 
cent. 



Deep blue. 



Pearly 


Blu- 


and vit- 


ish, 


reous. 


light- 


Trans- 


er 


parent 


i than 


to 


colon 


opaque. 





V. 



* 4 37 



V. 



Uses. 



See under heading Copper, 
etc. 



Sometimes it is cut and pol- 
ished for ornamental pur- 
poses. It is also sometimes 
used as a green pigment, 
and in the manufacture of 
the various salts of copper. 



See under heading Copper, 
etc. 



67 



Name. 



COMP. AND 

Percentage 
op Important 
Constituent. 



Genebal Characters and Associations. 



COPPER AND ITS COMPOUNDS.— Continued. 



Chryso- CuSiO» 
colla +2H s O. 

(Copper 

Sili- Copper, 

cate). 36*. 



Usually in form of incrustations, or filling seams* or botryoidal. 
Conchoidal fracture and rather sectile. Usually very impure. 

Usually associated with red copper ore, native copper, and mala- 
chite. 



Specific 



Before Blowpipe. 



Blackens in R. F. and yields water 
without melting. With soda on 
charcoal effervesces and yields a 
globule of copper. Easily soluble 
in acids. Copper reaction with 
borax and salt of phosphorus. 



Ataca- 
mite 
(Chlor- 
ide of 
Copper). 



Cu a ClH a O t . Conchoidal fracture. Brittle. Found as aggregation of crystals. 
Also massive, granular, fibrous, compact, and as sand. Province 
Copper, of Atacama, Chile. Also in Arizona. 

59.3* 



Cuprite Cu s O. 
(Red 
Oxide). Copper, 

88.8*. 



Commonly crystallized in octahedrons, etc., but often much 
modified. Also massive, granular, and earthy. Often mixed 
with oxide of iron. 



Gives off water in closed tube and 
forms gray sublimate. B. B. 
fuses and colors flame azure-blue 
with a green edge. 



On coal yields a globule of copper. 
In forceps fuses and colors flame 
emerald-green. Unaltered in closed 
tube. 



Melac- CuO. A black powder or dull-black masses and botryoidal concretions 

onite along with other copper ores. Ordinarily soils fingers when 

(Black Copper, massive or pulverulent. 

Copper 79*8*< Usually found disseminated among other ores of copper, and 

Ore). sometimes occurs in shining botryoidal concretions or dull 

friable masses. 



Reacts for copper. 



58 



Characters-. 



Treatment with Acids, etc. 



Heated in closed tube 
yields water and 
blackens (water 20 per 
cent). Decomposed 
without gelatinization 
by acids, silica re- 
maining behind. 

Easily soluble in acids. 



Easily and quietly solu- 
ble in strong HCU 
Concentrated solution 
gives upon addition 
of water a white pre- 
cipitate of subchloride 
of copper. 

The strong HC1 solu- 
tion gives no precipi- 
tate with addition of 
water. Sometimes ef- 
fervescesonaccountof 
presenceof impurities 



Color. 


Lustre. 


Streak 


Fusi- 
bility. 


Hard- 
mess. 


Sp.Ge. 


Crys- 
talli- 
zation. 


Magnetic 
before 

OR AFTER 

Heating. 


Blue to 
green. 
Often black 
to brownish 
when im- 
pure. 


Vitre- 
ous, 
shining 
to 
earthy. 


White 
when 
pure. 


Infus. 


2-4 


2.2 


Amor- 
phous 




Bright 
emerald to 
dark green. 


Ada- 
man- 
tine to 
vitre- 
ous. 


Apple- 
green. 


2 


3-3.5 


3.7 


IV. 




Red, cochi- 
neal-red to 
brown-red, 
but some- 
times 
nearly 
black. 


Earthy, 
ada- 
man- 
tine to 
sub- 
metal- 
lic. 


Brown, 
ish 
red, 
shin- 
ing. 


Easily 


3.5-4 


6 


I. 




Iron-gray to 
black to 
brown- 
black. 


Metal- 
lic to 
earthy. 


Gray- 
black 


With 
diffi- 
culty 


3-4 


6 


V. 





Uses. 



See under heading Copper, 
etc. 



See under heading Copper, 
etc. 



See under heading Copper. 
etc. 



See under heading Copper, 
etc. 



59 



Name. 



Com p. and 
Percentage 
op Important 
Constituent. 



General Characters and Associations. 



COPPBB AND ITS COMPOUNDS.— ContinuecL 

Tetra- Cu 8 S T Sbi. Often a valuable ore of silver, q. v. ; less frequently an ore of 

hedrite Very vari- copper commercially speaking. Several varieties which show 
(Gray able. different reactions. A closely related form is teunantite, sub- 

Copper), stantially Cu 8 As,S T , the antimony being replaced by arsenic. In 

Copper, this the copper is often partially replaced by silver (the " gray 

52.1*. copper" of local miners) in which the percentage of silver some- 
times reaches as much as 14 per cent. 
This mineral sometimes contains zinc and silver, and occasionally 
mercury. It is often associated with chalcopyrite, pyrite, sphal- 
erite, galena, and various other silver, lead, and copper ores; 
. ' ' also siderite. 



Specific 



Before Blowups, 



The roasted mineral gives on char- 
coal, after long heating a globule 
of copper; often also reacts for iron, 
antimony, arsenic, and mercury. 



Corun- 
dum 
(Emery, 
common 
granular 
variety 
colored 
black by 
magnet- 
ite). 



AlsOt. Very hard, being next in hardness to diamond. Sub-varieties are 

sapphire* rufiy, amethyst (oriental), topaz, and emerald, which are 
transparent or translucent and very valuable as gems. 
Usually associated with some member of the chlorite group, and 
a series of aluminous minerals in part produced from its altera- 
tion. 



Slowly but perfectly soluble in salt of 
phosphorus to a clear glass. When 
finely powdered and after long 
heating with cobalt solution gives 
a fine blue color. 



60 



Characters. 



Treatment with Acidc,btc. 



Reacts for copper, sul- 
phur, and antimony. 
Frequently copper re- 
placed by iron and 
zinc, as well as silver 
and mercury, while 
antimonyis frequently 
replaced by arsenic 
and bismuth. Decom- 
posed by nitric acid 
with separation of sul- 
phur and antimony 
trioxide. 

Not affected by acids 
or by heat, but ren- 
dered soluble by fu- 
sion with potassium 
bisulphate. 



Color. 


Lustre. 


Streak 


Fusi- 
bility. 


Hard- 
ness. 


Flint-gray to 


Dark 


Steel- 


I 


3-5- 


iron-black. 


gray. 
Metal- 
lic to 
splen- 
dent. 


gray 
to 

black 
and 
to 

brown 
and 
cher- 
ry- 
red. 




4-5 


Blue, red, 


Often 


Same 


Infus. 


9 


purple, yel- 
low, green; 


bright, 
vitre- 


as 
color. 






when less 


ous. 








pure gray- 
brownish, 










light blue 
and black. 




• 







Sp. Gr. 



4.7 



Magnetic 
brforb 

«>^»>mt OR AFTER 
ZATIOH. HmATmGm 



Crys- 

TALLI- 



III. 



Uses. 



See under heading Copper, 
etc. 




Corundum, and more espe- 
cially the impure form, 
crushed to different degrees 
of fineness, makes the abrad- 
ing and polishing material 
known in commerce as 
emery. This is used either 
as a powder or mixed with 
other materials to make it 
cohere; it is made into va- 
rious shapes for cutting, 
abrading, and polishing — 
e.g., emery-wheels, etc. 



61 



Name. 



Dia- 
mond. 



Com p. and 
Pbrcbmtagb 
of Important 

Constituent. 

C. 



Specific 



General Characters and Associations. 



Characterized by its extreme hardness. Brittle. Valuable as a 
gem and for cutting tools. 

Usually occurs in alluvial or driftal deposits in gravel, sand, or 
clay, or rarely in consolidated conglomerates or grits, associated 
with quartz, gold, platinum, octahedrite, rutile, hematite, ilmen- 
ite, topaz, corundum, tourmaline, garnet, etc. Supposed to be 
of original vegetable origin, the carbon having been dissolved 
and redeposited in some way not understood. 



Bbforb Blowpipe. 



At very high temperatures out of con- 
tact with the air it is transformed 
into a kind of coke, etc., etc. (See 
Dana's Min., pp. 4-6.) 



Emerald Be^AltSuO^ The distinctive characteristic, bright emerald green color, is sup- 

(Beryl). posed to be due to the presence of traces of chromium. Its 

Approx. hardness distinguishes it from apatite, and this character as well 

Silica, 670. as the formation of the crystals from green tourmaline. 

Alumina, Found in granite, gneiss, mica schist, dolomite, with phenacite, 

19*. chrysoberyl, apatite, rutile, etc. Widely distributed, but Muso 

Berylla or in New Granada, East Cordillera of the Andes, is the most cele- 

Glucina, brated locality. North Carolina has furnished some fine gems. 

140. The oriental emerald of jewelry is emerald-colored sapphire. 

Epidote. Very vari- A lime, iron, aluminum silicate. Quite hard and somewhat harder 
able. than chlorite, for which it sometimes maybe mistaken. A rather 

common rock constituent. 
Associated usually with quartz, calclte, pyroxene, feldspar, chlo- 
rite, hornblende, garnet, magnetite, pyrites, etc., especially in 
old and highly metamorphic formations. Sometimes also in 
eruptive rocks and in vein deposits. 

63 



Alone unchanged, or, if clear, be- 
comes milky white and clouded; 
after protracted heating the edges 
of splinters become rounded. A 
small percentage of water and or- 
ganic matter lost upon ignition, but 
color usually retained. 



Fuses with intumescence to a slaggy 
mass, dark brown in color, which 
is generally magnetic. 



Characters. 



Treatment with Acids,etc. 



Color. 



Lustre. Streak 



Unaffected by acids or Colorless to Ada- 
alkalies, black. man- 
tine. 



Fusi- 
bility. 



Infus. 



Hard- 
ness. 



Sp. Gr. 



3*5 



Crys- 
talli- 
zation. 



Magnetic 
before 

OR AFTER 
H RATING. 



Uses. 



Unacted upon by acids. 



Partly decomposed by 
HC1, but when pre- 
viously ignited, gela- 
tinizes with acid. De- 
composed on fusion 
with alkaline carbon- 
ates. (Dana.) 



Bright 


Vitre- 


White 


emerald- 


ous, 




green. 


trans- 
parent 
to 

trans- 
lucent. 




Pistachio- 


Vitre- 


Uncol- 


green, 


ous, 


ored, 


brown, yel- 


trans- 


gray- 


low, green- 


lucent 


ish. 


ish black, 


to 




gray, etc. 


opaque. 





5.5 



6-7 



3-5 



I. Diamonds, besides being 

largely used and highly 
_ __ _______ prized as jewelry, are em- 
ployed for cutting glass, for which purpose the 
natural edge of a crystal is best adapted. 
Compact and amorphous varieties known as 
bort and carbonado are employed for cutting 
purposes in jewelry. Bort is used as a powder 
for cutting diamonds and other hard stones, and 
very frequently when set in the edges of boring 
tools (diamond drills) the whole stone or frag- 
ments are used for drilling holes in hard rock. 



7.5 2.6-2.8 HI. 



Used as a gem when clear 
and free from flaws. 



V. 



Name. 



Feld- 
spars. 
Common 
rock con- 
stituents, 
espe- 
cially of 
igneous 
rocks. 



Com*, and 
Percentage 
of Important 
Constituent. 

Essentially 
silicates of 
alumina, 
with vari- 
able pro- 
portions of 
silicates of 
potash, 
soda, mag- 
nesia, and 
lime. 



Specific 



General Characters and Associations. 



Varieties: Or t hoc last. — Potash or common variety. Cleaves in two 
directions at right angles. All other feldspars cleave at oblique 
angles. Found in crystalline rocks, being a constituent of gran- 
ite, gneiss, syenite, etc., and also of the eruptive rocks — por- 
phyry, trachyte, phonolyte, etc. 



Oligoclase. — Soda-lime variety, 
above. 



Occurrence much the same as 



Before Blowpipe. 



Fuses quietly. Colors flame violet or 
lavender (potassium). (See Flame 
Colors. ) Some specimens give soda 
flame. 



Fuses quietly. Colors flame orange- 
yellow (sodium). (See Flame 
Colors.) 



Albite. — Soda variety. Usually distinguishable from orthoclase 
by its greater whiteness. Occurrence much the same as above. 

The above are very variable, and distinguished from quartz by 
their inferior hardness, the shape of the crystals, and other 
well-known physical characteristics. 



Fuses quietly. Colors flame an in- 
tense orange-yellow. (See Flame 
Colors, Appendix.) 



Fire-clay. The clay used for fire-brick should be a nearly pure silicate of alumina and free from lime and the alkalies. £tour- 
clay used for making bricks vary very widely in composition and in the results obtained. Grades insensibly into 
association with coal, is in making fire-bricks and retorts for blast-furnaces , for other metallurgical works \ and for 
made in large quantities, and are used for fire-proof partitions \ etc, , for safe- and refrigerator-linings, and for other 
of fire»cltys are also largely used by paper-manufacturers in glaring and weighting paper. A considerable quantity is 



64 



Characters. 

Treatment with Acids, etc. 



Color. 



Not acted upon by Colorless, 
acids. pale yellow, 

white, flesh- 
red, gray, 
green. 



Not acted upon by White and 
acids. flesh-red. 



Not acted upon / by Colorless, 
acids. white, dull 

green. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 
ness. 



Sr. Gr. 



Vitre- 
ous to 
pearly. 



Vitre- 
ous, 
etc. 



Vitre- 
ous, 
etc. 



Uncol- 
ored. 



Un col- 
ored. 



3-5 



Crys- 

TALLl* 
ZATION. 



Magnetic 

BEFORE 
OR AFTER 

Heating. 



6 2.5 . V. 



6-7 a.6 VI. 



Uncol- 4 
ored. 



6-6.5 



3.6 



VI. 



^Tfie chief use of feldspar Is 
in the manufacture of cer- 
tain kinds of pottery, for 
which the purer grades are 
very desirable. Orthoclase 
is used in a finely powdered 
state as a glaze for porcelain 
and to a small extent in 
jewelry, though sunstone 
(aventurine feldspar) and 
moonstone are mostly oligo- 
clase. 

When found in abundance it 
is used like the above in the 
manufacture of the finer 
kinds of pottery. 



bridge clay contains from fio* to 70* silica and from 20* to 30* alumina, with traces only of iron and lime. Of course the kinds of 

pure kaolin, q. v. Uses. — The principal use of the purer and whiter clays, and the clay, if suitable t found so generally in stratified 

gas-works, Refractory clay is also used for making sewer-pipe % water-pipe^ and chimney-tops. Porous brick and terra-cotta lumber are 
purposes where nonconducting and fire-proof materials are required. Roofing-tiles and hollow bricks are also made. The purer forms 
used in the manufacture of alum. Ordinary building-brick is made from the much more impure and common varieties of clay. 



65 



Nam.. 



Fluor- 
spar 
(Fluor- 
ite). 

Common 
vein- 
stone. 



COMP. AND 

Percentage 
of Important 
Constituent. 

CaF,. 



Specific 



General Characters and Associations. 



Characteristic phosphorescence on heating is distinguishing feat- 
ure. It is valuable as a fluxing material, for which purpose it 
is often preferred to carbonate of lime. Not very abundant in 
the United States. Frequently occurs in veins in connection 
with and as the gangue of many of the metallic ores, especially 
of lead. The veins may traverse nearly any kind of ore, but 
fluor-spar is usually found in gneiss, mica-slate, clay-slate, lime- 
stone, sandstones, and sometimes in volcanic breccia. 



Before Blowpipe. 



When gently heated gives out green- 
ish or purplish phosphorescence 
temporarily and colors flame red. 
Turns white and decrepitates, and 
ultimately fuses to an enamel which 
gives an alkaline reaction on test- 
paper. 



Fuller's 
Earth. 



An earthy hydrated silicate of alumina, composed, when pure, of 45* silica, 20* to 25* alumina and water. Like 
fulling or cleansing of woollen fabrics and cloth , since it was an excellent absorbent of the grease and oil contained in them. 



Garnet. fcxceed- 
Common ingly 
rock variable, 

constitu- 
ent. 



Alumina, iron, and chrome garnets, all brittle. Generally impure 
and porous. 

Common In mica schist, gneiss, syenite and chlorite schist, and 
other metamorphic rocks. Also in crystalline limestone, dolo- 
mite, granite, etc., sometimes in serpentine and volcanic rocks, 
etc. 



Most garnets fuse easily to a brown 
or black glass, but fusibility varies, 
and chrome garnet is almost infusible. 
(Compare cassiterite.) 



66 



Characters. 





Color. 


Lustre. 


Strbak 


Fusi-" 

BIL4TY. 


Hard- 

MESS. 


Treatment with Acids,stc 












In closed tube decrepi- 


All colors. 


Vitre- 


Whit- 


3 


4 


tates and generally 




ous, 


ish. 






phosphoresces. Fused 




trans- 








with bisulphate of po- 




parent 








tassa in closed tube 




to sub- 








yields vapors of hy- 




trans- 








drofluoric acid, which 




lucent. 








corrode glass. Same 












effect when treated 












with sulphuric acid. 













Macnrtic 

BEFORE 
..«..%... OK AFTER 

zatiok. Heatimo , 



Crys- 

TALU- 



Sp. Gr. talu- before tj 



3.2 I. Fluor-spar is used and is 

very desirable as a flux in 
metallurgical processes, as 
in the reduction of alumi- 
num; also largely in making 
glass, in the manufacture of 
hydrofluoric acid, in making 
paints, enamels, and mineral 
wool. Sometimes made into 
very beautiful vases and 
ornamental objects. 

other soft, aluminous minerals, absorbs grease. Uses. — Fuller* s earth was formerly largely used as an absorbent in the 

Other substances have been substituted^ however \ and the consumption has fallen off greatly in consequence. 

Not decomposed by 
HC1, but if first ig- 
nited, then pulverized 
and treated with acid, 
they are decomposed, 
and the solution 
usually gelatinizes 
when evaporated. 



Red to cin- 


Vitre- 


White. 


Va- 


namon- 


ous. 




rious, 


brown, 






3-6. 


black, 






most 


green, 
emerald- 






varie- 
ties 


green, but 

rarely 

colorless. 






easily 



3-4 



I. The fine specimens are prin- 

cipally used as gems. The 
gem known to the ancients 

, as "carbuncle" — and to a 

certain extent the term is used at the present day — is simply 
a deep red variety of garnet cut in a certain fashion. The 
chief use of the varieties not suitable for gems, especially the 
variety almandite % is in the manufacture of sand-paper or garnet- 
paper. It is utilized for abrasive purposes in the manufacture 
of boots and shoes, and also to a less degree in the woodwork- 
ing industry. For metals emery is usually preferred. The 
garnet used in the manufacture of garnet-paper is found to be 
harder, sharper, and more durable than quartz, and is preferred 
to quartz for this purpose, though costing many times as much. 



$7 



Coup, and Sracmc 

Namb. orluZoKTAirr Gekeeal Characters akd Associations. 

Constituent. Bbpoeb Blowpipe. 

GOLD AND ITS COMPOUNDS. 

Gold may be generally recognized by its physical characters — color, lustre, malleability, and specific gravity. When a gold 
regia. If this solution be dropped on to a filter-paper and one drop of stannous chloride be added, a purple-red color is obtained, 
precipitate being dissolved and tested with stannous chloride, it is separated from the easily volatile metals by simply heating on 
cupellation. -The copper is absorbed into the cupel with the lead, while the silver remains alloyed with the gold. If the globule 
of silver, which, after fusing on charcoal in O. F., will impart an opaline character to the cool bead. If it be more of a silver-white 
with nitric acid by application of heat. The silver is thus dissolved, and the gold remains as a dark powder or spongy mass. If 
native metal. Iron pyrites is frequently found combined with a small percentage of gold, but the other minerals with which it is 

Native. Au. Easily recognized by its physical properties. No cleavage, hackly Fuses easily. Is not acted on by 

fracture, and great malleability and ductility. fluxes. 

The association and distribution of native gold and its ores 
have to be considered under two heads: (a) as it occurs in 
mineral veins, and (4) as it occurs in alluvial or other superficial 
deposits which are derived from the erosion of the region con- 
taining these mineral veins or contact deposits. With regard to 
the first it is found generally in quartz veins or reefs travers- 
ing slaty or crystalline rocks, schists, talcose schists, and many 
kinds of eruptive rocks. It is most frequently associated with 
quartz and iron pyrites, but is also very often found in connec- 
tion with galena, blende, magnetic and specular oxide of iron, 
and other minerals, and also very often with silver ores. It is 
quite frequently associated with the tellurium minerals, q. v. It 



may be said, generally speaking, that gold is usually found in rocks of a silicious character, and is not 
often found in basic rocks, although there are many exceptions to this rule. With regard to the 
second class (alluvial or drift deposits, known as " placers ") the associated minerals are generally those 
of great density and insolubility, such as minerals of the platinum group, tin-stone, chromic iron ore 
sometimes precious stones, etc., etc., admixed with quartzose pebbles or sand. 

68 



Characters. 



Treatment with Acids,etc 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 

NESS. 



Sp. Gr. 



Crys- 
talli- 
zation. 



Magnetic 
bbporb 

OR AFTER 

Heating. 



Uses. 



compound is heated on a carbonized match or charcoal in R. F.,a yellow malleable bead is obtained, which dissolves in aqua 
Gold can be readily detected in its solutions, inasmuch as it is obtained in a metallic state by reducing agents. The well-washed 
charcoal in O. F. If associated with copper or silver, it must be fused with a large excess of pure metallic lead and subjected to 
is quite yellow, this is a proof that but little silver is present. It is then to be tested with salt of phosphorus to prove the presence 
color, the amount of gold will be small, and in order to prove its presence and approximate quantity the globule must be digested 
this powder or mass be washed and fused with borax on charcoal, it will yield a globule of metallic gold. The chief source is the 
associated are rare. Uses. — Used as a money metal \ for gildings for jewelry \ and for a vast number of ornamental objects. 



Insoluble in any single 
acid, but readily in 
nitro-hydrochloric. 



Yellow, 
rarely 
orange- red, 
and inclin- 
ing to sil- 
ver-white. 



Dull 
metal- 
lic. 



Like 
color. 



2.5-3 2 «5~3 12-20 



See under heading Gold, etc. 



Nam*. 



Comf. AND 
percentage 
of Important 
Constituent. 



Spkcific 



General Characters and Associations. 



Before Blowpipe. 



GOLD AND ITS 

Aurifer- Variable, 
ous Iron 
Pyrites, 
etc. (See 
Pyrite.) 



COMPOUNDS.— Continued. 



Gold is found intimately, but usually in very small quantities, associated with pyrites, but the best opinion 
alteration. In fact, they are found imbedded in each other, but with no further relation than that they 
chalcopyrite, marcasite, etc., when associated with gold. 



Sylvan- 
ite, etc. 
(Tellu- 
ride of 
Gold.) 



(AgAu)Te, 

Gold, 

24- 5*. 

Silver, 

13-4*. 
.and varia- 
ble, some- 
times little 
or no silver 
present. 



A telluride of gold and silver in which the proportion of gold and 
silver is nearly equal. Transylvania, California, and Colorado. 

Calaverite is a variety in which the proportion of gold to silver is 
6 to 1. 

Nagyagitc, another variety, is a sulpho-telluride of lead and gold 
and antimony. 

At Cripple Creek, Colo., very little silver is present, the com- 
bination being simple telluride of gold. The associated minerals 
are usually quartz, pyrites, sometimes fluor-spar, etc., etc. 



After long heating gives a yellow 
malleable metallic globule. On coal 
fuses to a dark gray globule, de- 
positing at same time a white coat- 
ing, which in R. F. disappears, 
tinging flame bluish green. 



70 



Character*. 



Treatment with Acids, etc 



Color. 



Lustre. Streak 



Fusi- 

BIUTY. 



Hard- 
ness. 



Sp. Gr. 



Crys- 
talli- 
zation, 



Magnetic 
before 

OR AFTER 

Heating. 



Uses. 



is that there is no chemical combination of the two. It occurs in pyrites or attached to pyrites or the oxide resulting from its 
were deposited together, one on the other. This is also true of the other sulphides, such as galena, zinc blende, arsenopyrite, 



Incompletely soluble in 
HNO,. Soluble in 
aqua regia, with sep- 
aration of chloride of 
silver. In open glass 
tube yields a white 
sublimate of tellurium 
dioxide which is gray 
near the assay, and 
which, when played 
upon by flame, fuses 
to transparent drops. 



Steel-gray 


Metal- 


Steel- 


to silver- 


lic, bril- 


gray 


white, rare- 


liant. 


and 


ly brass- 




like 


yellow. 




color 



Easily 1.5-2 



See under heading Gold, etc. 



71 



Namk. 



CoMP. AMt> 

Percentage 
of Important 
constituent. 



General Characters amp Association!. 



Specific 



Bbfobb Blowpipb. 



Graphite C. 



Resembles molybdenite (q. v.), but differs in being unaffected by 
the blowpipe and acids, and greatly in specific gravity. The 
same characters distinguish the granular varieties from any 
metallic ores they resemble. 

Usually found in very old crystalline rocks of sedimentary origin 
in irregularly bedded veins or masses, but is often found as a 
constituent of mica schist or gneiss, and sometimes of crystalline 
limestone. Sometimes found disseminated through these rocks 
as foliated laminae or scales, and occasionally in the older sand- 
stone. Being derived from organic matter, it is naturally found 
in rocks of an originally sedimentary character, though these 
are now usually greatly metamorphosed. The so-called vein 
graphite is usually associated with calcite and quartz. Pyroxene, 
mica, and apatite are sometimes found with it. 



Very soft. Soils the fingers and feels 
greasy. Absolutely infusible B. B. 
If held in zinc forceps and dipped 
into solution of sulphate of copper, 
becomes quickly covered with cop- 
per. At a high temperature burns, 
but not more easily than diamond, 
q.v. 



Halite 
(Rock 
Salt) 


NaCl. 
Chlorine, 


(mas- 
sive). 


39-4*. 
Sodium, 
60. 6*. 



Crackles or decrepitates when heated. 
Fuses easily, coloring flame a deep 
yellow. 



Crystalline form of common salt. Distinguished by its solubility 
and saline taste. Cubic crystals. Furnishes the greater part of 
the supply of salt. 

Occurs in extensive but irregular beds in many stratified forma- 
tions usually associated with gypsum, anhydrite, calcite, clays, 

or sandstone. In Chile often associated with the nitrate of soda 

deposits. Common salt is often found covering large areas representing the drying up of salt lakes; 
also as an efflorescence in arid and semi-arid regions, and also in solution forming salt springs or in 
the water of the ocean and all inland salt seas. 

72 



Characters. 

TREATMENT WITH ACID3,«TC. 

When treated in a plat- 
inum spoon with nitre 
deflagrates, affording 
carbonate of potassa, 
which effervesces in 
acids. Unaffected by 
acids. 



Soluble In 3 parts of 
water. With nitrate 
of silver, white pre- 
cipitate of silver chlo- 
ride. 



Colos. 



Iron-black 

to dark 
steel-gray. 



Lustr*. Stkbak 



Ftoi- 

BIL1TY. 



Hard- 
ness. 



Sr.Gs. 



Magnetic 

BEFORE 

.._,.„ OR AFTER 

ZATION - Heating. 



Crys- 

TALLI- 



Metal- 
lic, 

some- 
times 
dull 
earthy 



Black Infus. 1-2 2-2.2 III. 



Colorless, 
white, yel- 
low, red, 
bluish, 
purple. 



Vitre- 
ous. 



White. Easily 2.5 a.15 L 



Usss. 



Graphite is extensively em- 
ployed as a lubricant in ma- 
chinery, for making refrac- 
tor v crucibles, for stove 
polish, paints, in the manu- 
facture of lead-pencils, and 
generally in the manufacture 
of refractory articles and 
somewhat in the manufac- 
ture of electrical supplies. 
By far the most part is em- 
ployed in the manufacture of 
crucibles, after which comes 
the consumption for stove 
polish, for which an inferior 
grade of mineral suffices. 
The amount used for lead- 
pencils is comparatively 
small, but the best quality is 
required. 

This mineral is the chief 
source of common salt. It 
is not considered necessary 
to mention the manifold 
uses to which this compound 
is put. 



78 



Namk. 



Horn- 
blende 
(Amphi- 
bole). 

(Com- 
mon 
rock 

constitu- 
ent.) 



COMP. AND 

Percentage 
or Important 
Constituent. 

Essentially 
bisilicates of 
various pro- 
toxides and 
sesquioxides. 
The protox- 
ides may be 
magnesia, 
lime, soda, 
potash, and 
the protox- 
ides of iron 
and man- _ 
ganese. The 
the peroxides 



Specific 



G enseal Characters and Associations. 



Numerous compounds, which it is not necessary to mention. Very 
tough. Compare pyroxene, to which it is closely allied, in com- 
position as well as appearance. Massive (hornblende schist). 
Chief varieties are tremolite and actinolite, to which when fibrous 
the name asbestus is often given; also referred to as mountain 
leather ', mountain paper \ mountain cork, or mountain wood, (See 
Asbestos.) 

Occurs abundantly in the older metamorphic rocks, such as in 
many crystalline limestones, granites, and schistose rocks. It 
occurs sparingly in serpentine and igneous rocks. 



sesquioxides are alumina andj 
of iron and manganese. 



Before Blowpipe, 



Swells up and fuses with effervescence 
to a black or grayish glass. 



HYDBOCABBONS. 

Compounds of carbon, hydrogen, and oxygen. These compounds are numerous, and form a great variety of economically 
under their proper heads. For sake of distinguishing between them the various coals are placed in a separate division, although 
quantities of paraffin, while this can be said of only a few of the coals. While the latter chemically considered possess many 

A peculiar hard pitchlike material, somewhat resembling coal. Some varieties soften a little in boiling 
water, and all are but slightly soluble in camphene. Not as fusible or as soluble in benzene or ether as 
asphaltum, but shows incipient fusion in candle flame. The same may be said of the following varieties, 
which differ from each other chiefly in the amount of oxygenation which they have undergone, which 
fact has had an important bearing upon their physical properties. They pass from one into the other 
by insensible gradations. Albertite is usually extremely brittle, with very distinct conchoidal fracture. 

Occurs filling irregular fissures in rocks of the Subcarboniferous or Lower Carboniferous age in Nova Scotia. 



a. 


Fixed 


Solids. 


carbon 




(about 86*) 


Albertite. 


much 




higher 




than in the 




following. 



74 



Characters. 

Treatment with Acids, etc. 

Not acted upon by 
acids, or only very 
slightly. 



Color. 


Lustre. 


Streak 


Fusi- 
bility. 


Hard- 
ness. 


Generally 
green to 
black. 


Vitre- 
ous, 
silky. 
Sub- 
trans- 
lucent 
to 
opaque. 


Uncol- 

ored 

or 

paler 

than 

color. 


a.5 


5-5 



Sp. Ge. 



Crys- 
talli- 
zation. 



Magnetic 

bepore 

or after 

Heating. 



Uses. 



important gaseous, liquid, and solid products, the composition and characters of the more prominent among which are stated 
they are also oxygenated hydrocarbons, one point of difference being that the substances here enumerated generally yield large 
characteristics in common with, they differ widely in physical and in other respects from, the following less well known varieties: 



Some varieties are not 
at all soluble, others 
partially soluble in oil 
of turpentine. Soft- 
ens a little in boiling 
water. 



Lustrous 
jet-black. 



Bril- 
liant to 
dull, 
vitre- 
ous. 



Black 



Imper- 
fect. 



IS 



1.09 Amor- 
phous 



76 



Name. 



COMP. AND 

Percentage 
of Important 
Constituent. 



Specific 



General Characters and Associations. 



Before Blowfife, 



HYDBOCABBONS.— Continued 



Graham- 
ite. 



Uintahite 
or Gil- 
sonile. 



More vola- 
tile mat- 
ter (illu- 
minating 
gas) than 
in albertite. 



Much like albertite, but differs from it in being entirely soluble in camphene; also harder. 

only imperfectly when heated. 
Occurrence much the same as the foregoing, in West Virginia. 



Melts 



Related to albertite, but tougher, with fracture conchoidal, and having very different properties. Fuses 

easily in candle flame. 
Occurs in true fissure veins traversing sandstones and shales in much the same manner as the above, 

in Utah, etc. 



Ozoker- 
ite. 



Simple hy- 
drocarbon 
contain- 
ing no 
oxygen, a 
paraffin. 



Like wax or spermaceti in consistency. It and kindred substances often referred to as "earthy wax." 
May be kneaded like wax. Softens in heat of hand. Feels greasy. Melts readily like sealing-wax, but 
will not adhere to paper unless very hot. Takes impression of the seal. Electrically excited by friction. 
Under high heat the interior may be drawn into threads. Wurtzilite is a jetlike variety which is sec tile, 
somewhat like gutta-percha, and slightly elastic, but brittle when cold; more elastic if quietly warmed. 
Fuses readily, but resists the ordinary solvents of bitumen. When warmed becomes more plastic. 

Occurs with former and related materials in Utah, etc., and, like 
the former, has probably some connection with the asphalt de- 
posits there. It is also found in Europe with coal or bituminous 
deposits; also associated with petroleum in sandstone in Galicia, 
Saxony, etc. 



76 



Characters. 

Treatment with Acids, htc 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 
ness. 



Sp. Gr. 



Crys- 
talli- 
zation. 



Magnetic 

BEFORE 
OR AFTER 

Heating 



Nearly completely sol- Pitch- or Lus- 

uble in camphene. No jet-black. trous, 

action with HC1 or bril- 

HNOt. Hant. 



Black 



Imper- 
fect. 



1-4 



Amor- 
phous 



Soluble in petroleum 
or warm oil of turpen- 
tine. Ether slowly 
dissolves powder. 



Soluble In boiling ether 
or benzene. The di- 
lute solution is highly 
fluorescent. 



Black. 



Lus- 
trous. 



Rich 
brown 



Easily 2.25 1.06 



White to 


Dull, 


Like 


Melts 


Soft. 


0.85- 


Amor- 


yellowish 


trans- 


color. 


at 




0.95 


phous 


brown and 


lucent. 




6i°C. 








darker 














shades. 















Amor- There is a limited demand 

phous for this mineral as well as 

the two former among the 
manufacturers of certain 
grades of carriage-varnish 
and stove-blacking. 

Largely used, especially in 
Russia, as a substitute for 
beeswax. The mineral is 
distilled, and the resulting 
wax is employed in the 

manufacture of candles, 

which are especially adapted for use in high latitudes. 
Refined ozokerite is used in the manufacture of waxed 
paper, for the lining of wooden vessels, in the manu- 
facture of varnish and blacking, for adulterating bees- 
wax, for calking ships, for making liniments, plasters, 
salves, shoemakers' wax, wax ornaments, toy figures, in 
the manufacture of heavy lubricants where body is 
requisite, and for any of the thousand or more uses to 
which beeswax is applicable. 



rt 



Name. 



COMP. ANt> 

Percentagb 
or Important 
Constituent. 



Specific 



General Characters and Associations. 



Brfore Blowpipe. 



b 

Solid to 
semi- 
liquid. 

Asphalt. 



HYDROCABBONS.— Continued. 

Mixture of Seems to be the residue after the distillation of the lighter and more volatile oils, being variable in corn- 
different position. Fusible and inflammable, and burns with bright flame. Is more or less soft, has a bituminous 
hydro- odor, often melts in heat of sun (at oo° to ioo°), and flows like wax, then becomes hard on cooling, 
carbons, It varies from tough and somewhat hard material to soft and viscid substances, according to composi- 
part of tion and different physical characteristics. It grades insensibly from the solid bitumen into the viscid 
% which are bitumen, maltha, or mineral tar (pitt asphalts), through which there is a gradation to petroleum. The 
oxy- thin varieties usually bespeak the presence of the '* lighter oils," which detract from its value as a 
genated. paving material. These lighter oils(vaporizable at about no° or below) are usually, however, sparingly 
present, while the heavy oils (vaporizable at from ioo° to 250*) constitute sometimes as much as 85* of 
the mass. 
Principal deposit is the famous pitch lake of Trinidad. There are similar deposits in Venezuela on the 
mainland. It is. however, widely distributed throughout the United States, either in beds or as 
impregnating sandstones, shales, and limestones, in Kentucky, Indian Territory, Texas, Utah, etc., 
largely admixed with extraneous material. Occurs in many places in Europe, but the better variety 
seems to be associated with limestone, as at Val de Travers. It is a very generally distributed 
mineral, and is found in many parts of the world. It occurs in many localities where petroleum is found. 



c. 


Principally 


Liquid, 


composed 




of mem- 


Petro- 


bers of the 


leum. 


paraffin 




series, 




with a 




smaller 




percent- 




age of 




olefincs. 




Variable. 



••Mineral oil." Density .6 to .85. Of many colors, but usually dark greenish brown. Disagreeable 
odor. Varies also in consistency from the thin flowing kind into those which are thick and viscous, and 
thence by insensible gradation into the solid bitumen or asphalt. 

Occurs most abundantly -in certain sandstone strata underlying the coal measures, as in Pennsylvania, 
West Virginia, etc. It is also found in limestone in Ohio, where this rock furnishes most of the pro- 
duction afforded by that region. It is not, however, confined to the older strata, but is frequently found 
in Tertiary strata, as in Russia. The exact origin of petroleum and the other hydrocarbons is unknown, 
but they are presumed to have had their origin in organic matter (vegetable or animal, or both) which 
accumulated in the sedimentary material in which these deposits are found. It is found in sedimentary 
strata of all ages, from Silurian up to Tertiary, in the United States more particularly in Silurian, 
Devonian, and Subcarboniferuus formations. Owing to the nature of its origin, it is not found in 
association with eruptive rocks. 

78 



L ,— 



Characters. 

treatment with acids.etc. 

In closed tube gives 
empyreumatic oil, 
some ammoniacal wa- 
ter, combustible gases, 
and leaves carbona- 
ceous residue. Does 
not color potash solu- 
tion. Powder boiled 
with ether imparts to 
it a wine- or brown- 
red color. Soluble 
mostly in ether and 
oil of turpentine, 
partly in alcohol, but 
some solid asphalts 
are not at all soluble 
in the latter. 

Soluble in benzene or 
camphene. 



COLOJL 


LUSTRE, 


Streak 


Fusi- 
bility. 


Hard- 
ness. 


Sr. G*. 


Crys- 
talli- 
zation. 


Usually 
black to 
brownish 
black. 


Dull 
like 
black 
pitch. 


Like 
color. 


Melts 
at 90 
to 
IOO° 
C. 


Varia- 
ble. 


i-r.8 


Amor- 
phous 



Magnetic 

BEFORE 
OR AFTER 

Heating. 



Uses. 



Dark yellow 
to brown, 
and nearly 
black and 
greenish 
brown. 



By far the greatest consump- 
tion of this mineral is for 
street-paving, but it is also 
used as a covering for many 
kinds of wooden, iron, and 
other constructions, so as to 
protect them from decay or 
rust. Used for preparing 
roofing-felts and for water- 
proof material for coating water-pipes, in me- 
chanical engineering for the foundations of 
dynamos, steam-hammers, and other ma- 
chinery where jarring is to be suppressed. 
It is employed in various forms in naval, 
military, sanitary, electrical and mining 
constructions. It is also employed in var- 
nishes, photography, and otherwise. 



0.6- 
0.9 



Petroleum and its products, 
besides being used as an il- 
luminant, and as a source of 
power and great heat in 

^_^_ _ _____ metallurgical processes, is 

employed for a vast number of other purposes. It is used in the pro- 
duction of gas, as an enricher of common coal-gas, and when refined the 
waste products are employed in the manufacture of the various kinds of 
aniline dyes, in the manufacture of paraffin candles, and in the manu- 
facture of many salves, etc., used in medicine. Crude petroleum, as 
well as some of the refined products, is largely used as a lubricant. 



W 



Namb. 



COMP. AND 

Pbrcbntacb 
of Important 
Constituent. 



Gbnbral Chaxactbrs and Associations. 



Spccific 



Bbfobb Blowpips. 



KYDBOCABBON8 —Continued. 

d. CH 4 . Volatile, inflammable, etc. 

Gaseous. Variable. Occurs in the same regions and under much the same conditions 
Natural as petroleum. Being volatile, when in connection with oil, 

Gas. it is usually found above the oil. It is frequently found, how- 

ever, in oil regions where the well yields nothing but gas. 



Infuso- 


Essen- 


rial 


tially 


Earth 


SiO,. 


(Tri po- 


Some- 


lite). 


times 




contains 




a small 




amount 




of water 



Earthy or sometimes chalk-like material, largely or entirely made up of silicious skeletons of diatoms or 
with line spicules of sponges. Feels harsh between the fingers, and glass is scratched when rubbed 
becomes opaque. Some yellow varieties containing iron oxide turn red. Soluble in hydrofluoric acid 
than quartz; also soluble in caustic alkalies, but more readily in some varieties than in others. 

Occurs in quite thick stratified deposits, sometimes beneath peat- 
beds, and is obtained for commerce in the following States: Maine, 
New Hampshire, Massachusetts, Virginia, California, Nevada, 
Missouri, etc. It is also found in many other portions of the 
world, as in Barbadoes, Bohemia, Sicily, Calabria, Greece, the 
Nicobar Islands, and Nova Scotia. In nearly all of these locali- 
ties the beds are of Tertiary age. In some regions it is hard 
and indurated through consolidation due to infiltrating waters. 
It thus graduates into chert and opal. 



80 



Characters. 



Treatment with Acids,btc 



COLOIL 



Lustre. Streak 



Fusi- 
bility. 



Hard* 



, Sr. Gr. 



Magnbtic 

BEFORE 
ZATIOK. HEAT1NGa 



Crys- 

TALLI- 



UtBS. 



microscopic plants, 
with it. Infusible, but 
somewhat more readily 



White or 
grayish, 
earthy or 
chalky, but 
often col- 
ored by 
various 
impurities. 



Earthy. 



Whit- 
ish or 
like 
color. 



Infus. 5.5-6.5 1.9-2.3 



Amor- 
phous 



Besides being used in its 
natural condition for light- 
ing, it has been extensively 
employed in the regions 
where it is found for heating 
and cooking in residences, 
and for a time to a large ex- 
tent it was used in the place 
of coke in the manufacture 
and treatment of iron, and 
in many manufacturing and 
industrial establishments. 

This is used and sold in com- 
merce as a polishing pow- 
der under the names " elec- 
tro-silicon " and i4 silex." It 
is also used for making 
solutions of soluble silica 
(soda silicate), and for pur- 
poses of a cement. Owing 
to its poor conduction of 
heat, it has been applied as 
a protection to steam boilers 
and pipes. It is sometimes 
used to give body to soap. 



81 



Name. 



Iridium. 

(Iridos- 
mine.) 



Com p. and 

Percentage 
op Important 
Constituent. 

Iridium and 
Osmium 
in differ- 
ent pro- 
portions, 
in which 
the irid- 
ium varies 
from 
40* to 70*. 



Specific 



General Characters and Associations. 



Generally in combination with osmium or platinum or allied 
metals. Harder than platinum. Usually in foliac or irregular 
flattened grains. Slightly malleable to nearly brittle. Hard- 
ness varies in proportion to amount of the other softer metals 
with which it is always alloyed. 

Usually found in alluvial or gravel deposits (placers) with grains 
of platinum, gold, chromic iron ore, etc. Small quantities are 
found in Oregon and elsewhere on the Pacific Coast. 



Before Blowpipe, 



Wholly unaltered B. B. or by fluxes. 



IRON AND ITS COMPOUNDS. 

With borax in O. F. oxide of iron gives a dark brown-red glass, which becomes pale-yellowish or colorless on cooling; in 
become magnetic when heated with soda on charcoal, and dissolve readily in HC1; sulphide of ammonium gives to their solution a 
excellent test is to add ferroc^anide of potassium to solution. A pale-blue precipitate indicates ferrous salts, and a dark blue 
borax orsalt of phosphorus bead becomes violet-blue or reddish purple when the R. F. is directed upon it, especially if tin be added, 
to boil. Set aside. If titanium is present, the solution becomes violet in color. The presence of chromium is also readily 



82 



Chabactbxs. 



Treatment with Acids, etc. 

Not attacked by acids, 
except slightly by 
heated aqua regia. 



Color. 



Lustre. Streak 



Pale steel- Metal- 
gray to tin- lie. 
white to 
lead-gray. 



Like 
color. 



Fusi- 
bility. 



Infus. 



HARD- 
NESS. 



6-7 



Sp. Gb. 



19-21 



Magnetic 

BSFORB 

, ATloll OR AFTBR 

ZATION. Hbatino 



Crys- 

TALU- 



Usxs. 



III. Owing to its hardness, its 

principal use is for the 
points which are affixed to 
the nibs of gold pens, and 
for the knife-edges of fine 
balances, for the tips of 
rubber-turning tools, for wire 
draw-plates, etc. An alloy 
of pure iridium and pure 
platinum has been adopted 
for the standards of weights 
and measures, on account 
of its indestructibility and 
other desirable attributes. 
In the condition of sponge 
and oxide it is used in pho- 

tography and the ceramic art 

for obtaining a dense black, also by 
jewellers for obtaining black under 
white enamel. In all such cases its 
use is due to its infusibility. 



R. F. bottle-green on cooling. With tin the green color is hastened Most of the compounds 
black precipitate, which is soluble in dilute HC1, distinguishing it from cobalt and nickel. Another 
precipitate, ferric salts of iron. The presence of titanium maybe detected by the fact that the 
and test made on charcoal. A better test is to add tin to concentrated HC1 solution, and continue 
detected. (See Chromic Iron.) 



This metal is put to more 
manifold and more useful 
purposes than any other 
known to man. It is not 
considered necessary to at- 
tempt to enumerate them. 



83 



Namx. 



Com p. and 
Pkrckntagk 
op Important 
constituent. 



Sfbcihc 



GkUBSAL CHARACTERS AND ASSOCIATIONS. 



UtON AND ITS COMPOUNDS.— Continued. 

Mag- FeaOi* Easily recognized by streak and strong magnetism, which dis- 

netite tinguish it from the following. Very common, hard, compact, 

(Mag- Iron, and massive ore. 

netic 72.39*. Occurs principally in metamorphic rocks and as grains scattered 

Iron through eruptive rocks. In great beds in the earlier stratified 

Ore). formations which are now often metamorphosed into granite, 

gneiss, and the various schists. Sometimes found in connection 
with the older limestones. In the western United States it fre- 
quently marks the outcroppings of fissure-veins or contact-de- 
posits, and in such cases it is usually superficial and owes its 
origin to the oxidation of iron pyrites contained in the vein. 

Hematite Fe t O|. Scaly, fibrous, and compact, columnar. Sometimes concretionary, 

Varieties reniform, or botryoidal (kidney ore). Red powder, and the mag- 

are: Iron, 70*. netism so easily induced in it by R. F., serve to distinguish it. 

Occurrence much the same as above. Often in great interbedded 
masses in the older crystalline or metamorphic rocks especially, 
but is found in rocks of all ages. Like magnetite, it often in 
the western part of the United States marks the outcrop or 
oxidized portion of fissure- veins, contact-deposits, isolated 
pockets in limestone, etc., which contain at greater depths 
large quantities of pyrites. Often intimately associated with 
magnetite, as in Michigan, etc. 



Befors Blowpipb. 



Magnetic before heating, usually 
strongly, but sometimes only feebly; 
sometimes having polarity. Reacts 
for iron. Generally fusible above 
5. In O. F. loses its influence upon 
the magnet. 



Heated In R. F. readily becomes mag- 
netic, and if treated with soda on 
charcoal is red uced to a gray mag- 
netic metallic powder. 



84 



Characters. 
Treatment with Acids, i 



Color. 



Lustre. Streak 



Fusi- 



Hard- 

NBSS. 



Sp. Gr. 



Crys- 
talli- 
zation. 



Magnetic 
before 

OR AFTER 

Heating. 



Us 



Reacts for iron. 



Iron-black. 



Splen- 
dent, 
metal- 
lic to 
subme* 
tallic 
and 
dull. 



Black 



5-5- 
6.5 



5.17 I. Both. See under heading Iron, etc. 



Reacts tor iron. 



Dark steel- 


When 


gray, iron- 


crystal- 


black to 


lized, 


brown-red 


splen- 


and reddish 


dent. 


varieties. 


Usually 




metallic 




to sub- 




metallic. 




Some- 




times 



Cher- 
ry-red 
to 

brown- 
ish-red. 



Infus. 5.5- 4.2- III. After. When pulverized it is some- 
or 6.5 5.2 , times used for polishing 

above metal. When in an earthy 

5. condition it is used in the 

manufacture of crayons, for 
polishing glass, and as a 
red paint. 



dull. 



85 



Name. 



Com p. and 
Percentage 
of Important 
Constituent. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



UtON AND ITS COMPOUNDS.— Continued. 
Fe.O.. 



Specular. 



Hard, compact, and crystalline. Massive. That from Lake 
Superior region generally spoken of in commercial language 
Iron, 70*. as hard specular, or hard red specular. 

In interbedded masses in crystalline rocks, as in Michigan, etc. 
A valuable ore. 



Same as above. 



(£) Fe a O». These varieties possess a foliated, scaly, or micaceous structure. This specular schist often resembles 

Mica- called itabiryte. Reacts as above B. B. and with acids. Variety of the preceding. Some kinds are soft 

ceous. Iron, 7u*. Like the above ores occurs in crystalline and usually schistose rocks. Michigan, etc. 

(c) Fe a Oj. Hematite in octahedrons, derived, it is supposed, from oxidation of magnetite, with which it is commonly 

Martite, guished by its purple streak. N. B. — Sometimes ore is found giving red streak, yet possessing 

Iron, 70*. to presence of magnetite in the mass. Michigan, etc. 



M 


Fe a O a 


Soft 




Hema- 


Iron, 


tite. 





7<*. 



A soft, earthy variety, but often very pure, 
ganiferous. (Abundant and valuable ore. 



Loose and uncompact to semi-consolidated. 
Michigan.) Sub-variety bluish. 



Often man- 



86 



Characters 

Treatment with Acid^btc. 



Color. 



Lustre. 



*«~ 2ZZ. ^ S '- G «- 



r»v«- Magnetic 
2r" . , before 

TALLI- __ „,--- 

_.__-,-, OR AFTER 
XATION. HbatinG- 



Use*. 



Same as above. 



mica schist, when it is 
and unctuous. 



associated. D i s t i n - 
magnetism, always due 



Dark steel- 


Perfect- 


Red 


Infus. 


5-5- 


gray to red- 


ly me- 


or red- 


or 


6.5 


dish-black, 


tallic. 


dish- 


above 




reddish, 


Often 


brown 


5- 




iron-black. 


splen- 
dent. 








Light to 


Splen- 


Red- 


Infus. 


5-5- 


dark steel- 


dent 


dish. 


or 


6.5 


gray. 


metal- 
lic. 




above 
5- 




Iron-black 


Sub- 


Pur- 


Infus. 


6-7 


to reddish 


metal- 


plish 


or 




black or 


lic. 


or 


above 




bronze tar- 




red- 


5. 




nish. 




dish 
brown 






Dull red, 


Earthy. 


Pur- 


Infus. 


Varla- 


reddish to 




plish 
brown- 
ish to 


or 


ble. 


yellowish 
brown. 




above 






reddish 


5- 





4-5 



III. After. See under heading Iron, etc. 



III. After. See under heading Iron, etc. 



After. See under heading Iron, etc. 
Some- 
times 
feebly 
before. 



Amor- After. See under heading Iron, etc. 
phous 



87 



Name. 



COMP. AND 

Percentage 
of Important 
Constituent. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



IRON AND ITS COMPOUNDS.— Continued, 



(A 
Fossil Ore 
(Lenticu- 
lar iron 
ore), etc 



(/) 
Red 
Shale 
Ore. 

(*) 
Red 
Ochre. 



Fe a O.. 
Iron, 70%. 



Fe, O.. 
Iron, 7<*. 



Fe.O.. 
Iron, 70*. 



Turgite. Fe 4 H t O T . 



Iron, 



66.2*. 



Commonly called fossiliferous red hematite. Oolitic or composed of aggregations of small, flattened, 
different sizes. Usually contains a large percentage of impurities (lime, clay, sand , etc.). Often includes 
fossil remains. This variety is both hematite and limonite in character, but more frequently the 
latter description it affords the characteristic yellowish powder. Another variety is argillaceous 
stone, which is hard, brownish black to reddish brown or dull red, Submetallic to unmetallic and has a red 
is thus easily distinguished from the clay iron-stones of the species brown clay iron-stone (limonite) 
stone (siderite). 



Often an admixture of hematite and limonite. 
impure. 



Compact, looking much like compact red shale. (Virginia, 



Earthy or pulverulent form (used for pigments), 
mixed with more or less clay. 



Soft and earthy. Often associated with the above. 



Often associated with limonite, for which it is frequently mis- 
taken, but it is harder, has a different streak, and decrepitates in 
closed tube. Often constitutes an exterior layer of limonite. 
When botryoidal has much the same smooth lustrous surface. 
Supposed to be intermediate stage in alteration of limonite to 
hematite. Another intermediate variety less common than this 
is goethite, containing 62.9* of iron and 10. 1* of water. Found 
with both hematite and limonite. Liver-brown color, reddish 
streak like limonite. The so-called velvet ore is frequently of 
this variety. 

Occurs with other ores of iron, especially in the older beds, and in 
intimate association with limonite. 



Heated in closed tube flies to pieces 
and yields water. 



88 



Color. 



Reddish to 
brownish. 



Characters. 



Treatment with Acids, etc 



concretionary grains of 
fossils or composed of 
former. When of the 
hematite or clay iran- 
streak. This species 
and ordinary clay iron- 



etc.) Generally very Reddish to 
brownish. 



Lustre. 



Dull. 



Earthy 
and 
dull. 



Streak 


Fusi- 
bility. 


Hard- 
mess. 


Red- 
dish 
brown 


Infus. 

or 

above 


4.5-6 


to 


5- 




pur- 
plish 
red. 






Red- 
dish to 
brown- 
ish. 


Infus. 

or 

above 

5- 


4.5-6 



St. Ge. 



Crvs- 

• TA LU- 
XATION. 



Magnetic 

before 

or after 

Heating. 



5 HI(?) After. See under heading Iron, et 



5 III(?) After. See under heading Iron, etc 



Usually impure, being Earthy red. 



Often used as paint. 



Like hematite^ 



Reddish 


Subme- 


black, dark 


tallic, 


red to 


satin- 


bright red. 


like, 




duil, 




earthy. 



Red. 



5-6 



4.14 



Amor- 
phous 



After. See under heading Iron, etc 



Namb. 



Com*, and 
Percentage 
of Important 
Constituent. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



IBON AND ITS COMPOUNDS.— Continued. 



Limonite 
(Brown 
Hema- 
tite). 
Varie* 
ties are: 



Bog 
Iron 
Ore. 



Yellow 
Ochre. 



2Fe 9 Oi. 
3H a O. 

Iron, 59- 8#. 



2Fe,0 8 . 
3H a O. 

Iron, 59 8*. 



2Fe a O $ . 
3H„0. 

Iron, 59.8*. 



Compact, often dense when pure. Botryoidal, stalactitic with 
compact fibrous structure within, but also massive, etc. Not 
crystalline. Tendency to form acicular, sometimes stalactitic 
concretionary masses, with long needle-like fibres radiating from 
common centre; but generally amorphous. Common ore. 

Occurs in rocks of all ages. It has resulted, it is supposed, from 
the decomposition of other iron-bearing rocks or minerals. 
This is shown by the stalactitic and other forms in which it 
occurs. Like hematite and magnetite it frequently marks the 
outcroppings of fissure-veins, having been produced by the 
decomposition of the original pyrites or siderite in the vein. 

Simply a vesicular and generally impure variety of the above. 
Recognized by its comparatively light weight, yellow color, and 
loose or porous texture. Often petrifying wood, leaves, etc. 

Usually superficial, and occurs in swampy places containing vege- 
tation — often decomposing — into which places have flowed 
waters containing iron in solution, the iron having been precipi- 
tated by the presence of the organic matter. 

Earthy or pulverulent form of above. Earthy, brownish, yellow to ochre-yellow, 
mixed with more or less clay, sand, etc. 



With difficulty fusible to a magnetic 
mass. Some varieties leave a sili- 
cious skeleton on salt of phos- 
phorus bead. 



Gives all the reactions of the above. 



Usually impure, being 



90 



Characters. 

Treatment with Acids, etc. 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 
ness. 



Sr. Gr. 



Crys- 
talli- 
zation. 



Magnetic 
before 

OR AFTER 

Heating. 



Uses. 



Reacts for iron. Yields 
much water (of which 
it contains 14.5* and 
often more) in closed 
tube. Soluble, but 
with difficulty, in HC1. 
leaving frequently a 
silicious residue. 



Brown, 


Dull, 


various 


earthy 


shades, 


to sub- 


yellow. 


metal- 


black. 


lic. 


Never 


Some- 


bright. 


times 




silky. 



Brown- 
yellow 
to 
yellow. 



5—5.5 3.6-4 Amor- After. Limonite is also used, like 
phous hematite, for polishing me- 

tallic buttons and other 
articles. When earthy it is 
a common material for 
paint. 



As above. 



Yellowish to 
brownish. 



Dull. 



Brown- 
yellow 
to 
yellow. 



4-4.5 



Varia- 
ble. 



Amor- 
phous 



After. See under heading Iron, etc. 



like " Red Ochre," 



After. 



Used as a paint or in paint- 
mixtures. 



91 







COMP. AMD 


Name. 


Percentage 


op Important 




Constituent. 


IBON AND ITS C< 


- 


Siderite 


FeCO,. 




(Spathic 




t 


Iron 


Iron, 48.2*. 




Ore) or 






Iron 






Carbon- 






ate. 






Varieties 






are: 






Clay 


FeCO,. 




Iron- 






stone, 


Same, but 
very va- 
riable, ac- 
cording to 
impuri- 
ties. 




Black 


Same, but 




Band 


very va- 




Ore. 


riable, ac- 




Sub va- 


cording to 




riety of 


impuri- 




above. 


ties. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



Becomes magnetic upon heating R. F. 
With borax, gives reaction for 
iron. Decrepitates in closed tube 
and gives off CO, blackens and 
becomes magnetic. 



Often crystalline. Worked extensively in Europe. 

Occurs in many series of stratified rocks from the oldest to the 

youngest. Frequently found as stratified deposits in connection 

with coal formations, but it is also found in large irregular de- 
posits in limestone. Less frequently it is found forming part of 

the frilling of fissure-veins, when it is usually crystallized and 

associated with the metallic ores. In the former cases its 

occurrence is usually massive, and as such it is an important ore 

of iron. Ankerite, crystallized dolomitic variety. 

Name commonly given to compact, earthy, or stony kinds of above, which are rendered impure by an 
sand. In many formations, especially among the coal measures (England, etc.). Fracture finely granular, 
gives out an argillaceous odor when breathed upon. Sometimes as flattened spheroidal concretionary 
or oolitic; also granular to massive. Sometimes, when reddish in color, consists of impure hematite, 
of impure limonite; when unoxidized, however, is simply a more or less impure iron carbonate. 

This variety of the above occurs in rocks of all ages, the specular 
variety (argillaceous hematite, see fossil ore) being mostly 
confined to the older rocks. Also described as being the result 
of igneous action about some volcanoes, as at Vesuvius. (Dana.) 

A common variety of above, occurring in coal measures, and containing sometimes as much as 25* to 30* of 
A valuable ore in England, where the ore sometimes contains enough carbonaceous matter to effect the 
lie state without addition of anything except limestone. 



CHARACTER*. 

Treatment with Acids, etc. 



Soluble in heated HC1, 
with effervescence 
(CO a ), which is also 
given off when the 
ore is heated in closed 
tube. 



admixture of clay or 
Easily scratched, and 
masses of various sizes, 
or, if brown or yellow. 



Color. 


Lustre. 


Streak 


Fusi- 
bility. 


Hard- 
ness. 


Ash, yellow- 


Vitre- 


White 


4-5 


3.5-4 


ish and 


ous, in- 


or 






brownish 


clining 


uncol- 






gray to 


to 


ored 






brown-red. 


pearly. 


ex- 






Sometimes 




cept 






green and 




by im- 






white. 




puri- 
ties. 






Yellowish 


Dull. 


Whit- 


45 


3-7 


brown to 




ish or 






reddish 




gray- 






gray. 




ish. 







Sf. Gk. 



3-8 



r%»«« MaghetIc 

SET MFO *» 

J™*™ OR AFTER 

ZATION. H , ATIHC# 



Uses. 



III. 



After. See under heading Iron, etc. 



3.4 



Amor- 
phous 



After. See under heading Iron, etc. 



carbonaceous matter, 
reduction to the metal- 



Grayish 
black. 



Earthy, 
dull. 



Dark 

gray, 
etc. 



3.5 



Amor- 
phous 



After. See under heading Iron, etc. 



98 



Name. 



Com p. ANt> 
Percentage 
of Important 
Constituent. 



General Characters and Associations. 



Specific 



IRON Ain> ITS COMPOUNDS.— Continued. 



Titanic 
Iron Ore 
(Ilmen- 
ite or 
Menac- 
canitc). 



Chromic 
Iron. 

Iron 
Pyrites. 
Varieties: 



(TiFe),0,. 
Variable. 

If normal. 
Titanium, 

Iron, 36.8*. 

(Chrom- 
ite.) 

FeS,. 

Iron, 46.6*. 
Sulphur, 
53-4*- 



Marcasite 


FeS,. 


(Cocks- 




comb 


Iron, 46.6*. 


'Pyrites); 


Sulphur, 


(White 


53-4*. 


Iron 




Pyrites). 





Before Blowpipe. 



A hematite in which part of the iron is replaced by titanium. The 
presence of titanium is highly prejudicial to the value of any 
iron ore and, unless the quantity is very minute, renders it 
worthless as an ore of iron. 

Occurs in massive beds in gneiss and other crystalline rocks, also 
disseminated through these rocks and as iron-sands (iserine). 

Frequently associated with magnetite. 

See Chromium and its Compounds. 



Common pyrites. Distinguished from copper pyrites by its su- 
perior hardness and paler color. Cubes with striated surfaces, 
striae at right angles to one another. Brittle with conchoidal 
uneven fracture. Common source of sulphuric acid and often 
auriferous. 

Occurs abundantly in rocks of all ages, frequently disseminated 
through them, from the oldest crystalline rocks to the most 
recent alluvial deposits. A very common mineral in fissure- 
veins and contact-deposits. It is yery frequently associated with 
such minerals as quartz, galena, blende, copper pyrites, etc., etc. 

Same as above, but of different crystalline form. Sometimes 
called capillary pyrites, but this term properly applies to sul- 
phide of nickel (millerite). 

Associations the same as above. 



94 



Feebly magnetic. To borax or salt 
of phosphorus bead imparts an in- 
tense brown-red color in R. F., 
which, if tin be added, changes to 
violet red. 



Gives only reaction for iron. Gives 
off sulphur B. B. on charcoal, burn- 
ing with a blue flame. 



Sometimes contains little arsenic. 
More liable to decomposition than 
ordinary pyrites. 



Characters. 

Treatment with Acids, etc. 



Colo*. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 
mess. 



Sp. Gr. 



Magnetic 
before 

«.~.,v» OR AFTER 

ZATIOW. Hbat1wg . 



Crys- 

TALLI- 



U&ES. 



Partially dissolved in Iron-black. 
HC1. Concentrated 
solution boiled with 
tinfoil gradually as- 
sumes a violet color. 



Sub- 
metallic. 



Sub- 
metal- 
lic, with 
black or 
brown- 
red 
powder 



Infus. 



5-6 4-5-5 



III. Both. 



See under heading Iron, etc. 



When heated in closed 
tube gives off sulphur 
and yields a magnetic 
residue. But slightly 
affected by H CI. HNO. 
dissolves it, leaving 
residue of sulphur. 



Very pale, 
brass-like, 
yellow. 



Splen- 
dent, 
metallic 
to glist- 
ening, 
nearly 
uniform 



Brown- 
black to 
green- 
ish 
black. 



Easily 6-6.5 4.9 



After. Large amounts of sulphuric 
acid and sulphur are pre- 
pared from pyrites, though 
native sulphur {q. v.) is also 
very largely used for the 
production of sulphuric acid. 
It would be difficult to over- 
estimate the commercial im- 
portance of the latter. 



Same as above. 



Pale-yellow, 


Metal- 


Black- 


bronze, to 


lic. 


ish 


white. Color 




gray to 
brown- 
ish . 


deepens on 




exposure. 




black. 



Easily 6-6.5 4-3 IV. After. 



Used for the same purposes 
as ordinary pyrites, and to a 
small extent in *ewelry. 



95 



Namk. 



COMP. AND 

percentage 
of Important 
Constituent. 



Specific 



General Characters and Associations. 



Franklin- 
ite 


(FeZnMn) 

+ 
(Fe,Mn a )0 4 




Variable. 


Kaolin or 
Kaolinite 
(China- 
clay). 


AUOs. 
2SiO a + 
2H,0. 

Silica, 

46.5^ 
Alumina, 




3953<. 



Before Blowpipe. 



IBON AND ITS COMPOUNDS.— Continued. 

Magnetic Fe 7 S«. Like common pyrites, but magnetic, and different crystallization. 

Iron Py- Often contains nickel. Tarnishes quickly, 

rites Iron, 60.4*. Associations the same as the foregoing. 

(Pyrrho- Sulphur, 
tite). 39-5*. 

Resembles magnetite, but is of a more decided black color, and 
different streak. Usually feebly magnetic. (See also Zinc 
Ores.) Its chief value consists in the zinc which it contains. 

Found associated with red oxide of zinc and garnet in granular 
metamorphic limestone, also with silicate of zinc. Restricted 
to a few localities near Franklin, N. J. 

The soapy feeling distinguishes the clay, consisting of it or con- 
taining much of it. The unctuous and plastic character is owing 
to presence of kaolinite. Decomposition of feldspar yields it, etc. 
(See Dana's Min., p. 686.) Soft, clay-like, mealy, or compact. 

Often occurs in the form of scales in connection with the iron ores 
of the coal formation, also accompanying diaspore and emery or 
corundum. Nearly always a product of the alteration of feld- 
spar, and therefore associated with feldspathic rocks, usually 
granite. Has frequently to be separated from grains of quartz, 
with which it is associated before it is fit for use. 



Magnetic before fusion chief charac- 
teristic, but variable in this. In 
R. F. fuses to black magnetic 
mass. In O. F. converted into red 
oxide. 

On charcoal a faint zinc coating is 
obtained with R. F. A soda mix- 
ture in outer flame colored green 
by manganese. With borax reacts 
for manganese and iron. 



A blue color when 
cobalt nitrate (Al). 



moistened with 
Yields water. 



06 



Characters. 



Treatment with Acids,etc. 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 
ness. 



,Sp. Gr. 



Crys- 
talli- 
zation. 



Magnetic 
before 

OR AFTER 

Heating. 



Uses. 



But little sulphur in 
closed tube. Decom- 
posed by HC1 with 
evolution of hydrogen 
sulphide. 



Bronze-yel- 
low to cop- 
per-red. 



Soluble in HC1, with Iron-black, 
evolufon of chlorine 
in small quantities. 



Insoluble in acids. 
Yields water in closed 
tube. Water = 14*. 
Boiled with concen- 
trated sulphuric acid 
the alumina is dis- 
solved, leaving the 
finely - divided silica 
behind. 



White, gray, 
yellow, and 
brown to 
bluish. 



Metal- 
lic. 



Metal- 
lic to 
dull. 



Pearly 
to dull, 
earthy. 



Black- 
gray. 



Dark 
red- 
dish 
brown 
to 
black. 



Earthy, 
dull. 



Easily 



Infus. 



3.5- 
4.5 



4.5 



5.15 



III. Both. 



Both. 



Infus. 2-2.5 2.6 



V. 



Like ordinary pyrites, used 
for making green vitriol and 
sulphuric acid. 



The purest form is largely 
used in making the finest 
porcelain, and also for giv- 
ing body and weight to pap- 
er. Some impure and white 
clays are used for stone- 
ware, fire-bricks, retorts for 
gas-works, stove-pipes, etc., 
etc. Also used in calico- 
bleaching, and to a small ex- 
tent in the manufacture of 
alum, artificial ultramarine, 
and some other chemical 
products. (See Fire-clay.) 



97 



Name. 



COMP. AND 

Percentage 
of Important 
Constituent. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



LEAD AND ITS COMPOUNDS. 

They are easily fusible. With borax bead and with soda, and often alone, on charcoal a malleable bead may be 
coating is faintly bluish white when cold. When S and KI are added there is a greenish-yellow coating far from assay. Sublimes 
is nearly insoluble in water and dilute acids. Heated in open tube, white smoke and a non-volatile fusible sublimate is deposited 
characteristic coating will be produced on the coal. But sulphides, arsenides, etc., of lead must be treated in O. F. to produce the 

Assay, Appendix.) Uses.— Perhaps the largest use of lead is in the manufacture of the white lead of commerce (carbonate of lead) 

metallurgical processes ', as an alloy, e.g., with antimony in the manufacture of anti-friction metals and type-metal, with tin in the manu- 



Galena PbS. Easily recognized by the characteristic cubical cleavage which is 

(Galen- very easily obtained, or granular structure when massive, its 

ite). Lead, color, great weight, and softness. It is the chief ore of lead, and 

86.6*. is widely distributed, being very frequently associated with other 

metallic sulphides, such as pyrite, chalcopyrite, arsenopyrite, 

blende, etc., etc. It occurs in veins, the gangue of which is 

either quartz, calcite, barite, or fluor-spar, in granite, and nearly 

all varieties of rocks, but the larger deposits are usually found 

either in veins or in pockets, often of great size, in limestone 

strata. Very frequently contains considerable percentages of 

silver, and less frequently of gold. 

Cerussite PbCOt. Its brittleness and weight are distinguishing characteristics. 

(Lead Note. — The above two ores often contain silver, q. v. 

Carbon- Lead, Usually found in the superficial portions of deposits of galena, to 

ate). 83.5^. the alteration of which it owes its origin. 



With soda on coal decrepitates, covers 
the coal yellow, and yields lead 
globule. 



Yields lead alone on charcoal when 
heated carefully. In closed tube 
decrepitates, turns yellow, then a 
dark red, and returns to yellow on 
cooling. 



Characters. 



Treatment with Acids, etc. 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 
ness. 



Sp. Gr. 



Crys- 
talli- 
zation. 



Magnetic 
before 

OR AFTER 

Heating* 



Uses. 



obtained. Readily recognized by characteristic lemon or sulphur-yellow coating near assay when cold; red when hot. The outer 
readily. Volatile, tinging flame azure-blue. In nitric acid solution of salts of lead sulphuric acid gives a white precipitate, which 
on under side of tube. Oxides, carbonates, etc., may be reduced to the metallic state by heating in R. F. with soda, and the 
metal. Metallic lead obtained as above may be cupelled for silver on charcoal, or, better, on a bone-ash cupel. See B. B. Silver 
for use in paint. It if also largely made into pipes, sheet -lead, bullets, and shot; also extensively used as a flux in smelting and 
facture of solder, etc., and in the manufacture of certain kinds of glass, etc. 



Easily soluble in strong Lead-gray. Splend- 
nitric acid, with sepa- ent, 

ration of sulphur and metal- 

the formation of lead lie. 

sulphate. 



Lead- 
gray. 



2.5 



7-5 



When ground to an impalpa- 
ble powder and mixed in 
water with clay it is some- 
times employed for glaz- 
ing common stoneware, the 
earthen vessel being dipped 
into this liquid and then 
baked. 



Dissolves readily, with 
effervescence, in di- 
lute HNO,. WithHCl 
leaves a white residue 
of lead chloride, which 
is soluble in hot water. 



White, yellow- 


Ada- 


Un- 


ish, or gray 


man- 


col- 


or gray- 


tine, 


ored. 


ish black. 


vitre- 




When con- 


ous, 




taining cop- 


resin- 




per, tinged 


ous to 




blue or 


pearly. 




greqn. 







Easily 3.5 



6.4 



IV. 



99 



See under heading Lead, etc. 



Name. 



CoMP. AND 

Pbscbntacb 
or Important 
Constituent. 



Specific 



GENUAL CHARACTERS AND ASSOCIATIONS. 



Bbporb Blowpipe. 



MAGNESIUM AND ITS COMPOUNDS. 

These afford a clear rose red or pink color with cobalt nitrate after long heating. This distinguishes it from 
no precipitate in dilute HC1 solution. The fact that the precipitate from magnesia is soluble in water, while that from calcium is 
signalling. It is also used in refining metals to reduce the metallic oxides contained in them, owing to its great affinity for oxygen, 
agent, on account of the amount of magnesia which they contain, as, owing to their constitution, they have the property of attracting thephos- 
with it, and does not remain in the resulting pig iron, as it would otherwise do. 

Name of a group of minerals very closely allied, which are hydra ted silicates of aluminum with ferrous 
iron and magnesium. Sometimes thin foliated like mica, but often granular, massive. Texture granu- 
lar. Enter very largely into composition of schistose and slaty rocks. Chloritic schists and all their 
minerals are characterized by the green color which " is common with silicates in which ferrous iron is 
prominent " (Dana). 

It occurs often in chloritic and in many rocks as an alteration prod- 
uct, and associated with magnetic hornblende and tourmaline. 
Often enveloped in quartz. 



<*) 


Variable. 


Chlorites 




(Com- 




mon 




rock 




constitu- 




ents, 




mas- 




sive). 




(*) 


H 4 Mg 1 Si,O t 


Serpen- 




tine 


Magnesia 


(Mas- 


43* 


sive). 


Silica, 




44.1*- 



Usually compact, massive, also finely granular. It is a metamor- 
phic rock, the unaltered form being either sedimentary (e.g., 
limestone) or igneous (e.g., peridotite) in origin, but most 
serpentines are altered pertdotites. Rarely fibrous. Easily 
scratched or even cut with a knife. Smooth and a little greasy 
to feel. H yd rated silicate of magnesia. The variety chrysotile 
or bostonite is fibrous, and is largely mined as asbestos, q. v. 

Often in great dikes — even composing mountain masses — associated 
often with metamorphosed limestone, hornblende, slate, diallage 
rock, and greenstone. Certain metallic oxides are frequently 
found in connection with it, such as those of iron, nickel, and 
chromium. 

100 



Becomes brownish red B. B., and 
gives off water in closed tube. 



Characters. 

Tkbatmbmt WITH ACID8,BTC. 



Color. 



L.USTRR. STRRAK 



Fusi- 
bility. 



Hard- 



Sp. Gr. 



Crys- 
talli- 
zation. 



Magnetic 
before 

OR AFTBR 

Heating. 



Vm 



alumina. Distinguished from strontia and baryta by different flame-colors, and in the wet way by the fact that sulphuric acid gives 

not, suffices to distinguish it from the latter, etc. Uses .— The metal is chiefly used as an illuminant in photography and 

Bricks made of magnesian limestone (see dolomite) or magnesite, are employed in the steel industry as a desulphurizing and dephosphorizing 
phorus contained in the iron ore while the ore is being reduced; the phosphorus in consequence becomes entangled in the slag and goes off 



Yields considerable 
water in glass tube, 
which distinguishes it 
from talc, while its 
granular texture is 
sufficient to separate 
it from serpentine. 
Decomposed in sul- 
phuric acid. 

Decomposed by HiSO* 
and HC1, leaving resi- 
due of silica. From 
chrysotile the silica is 
left in fine fibres. 
This fact serves to 
distinguish the ser- 
pentine varieties from 
true asbestos, q. v. 



Dark olive- 


Pearly, 


Un- 


green, 


opaque 


col- 


grass-green 


to 


ored, 


to gray- 


partly 


green- 


green, etc. 


trans- 
lucent. 


ish. 



Infus. 1-6 



1.85 



Pale green 


Weak 


to greenish 


resin- 


black. 


ous, in- 


Sometimes 


clining 


mottled. 


to 




greasy. 



White Infus. 2-4 2.5 



See under heading 
nksium, etc. 



Mag- 



Extensively used in orna- 
mental and architectural 
work, though whole build- 
ings are sometimes made of 
this stone. The finer varie- 
ties, when cut and polished 
for ornamental purposes, 
are sometimes termed mar- 
ble. 



101 



Name. 



COMP. AND 

Percentage 
of Important 
Constituent. 



Specific 



General Characters and Associations. 



MAGNESIUM AND ITS COMPOUNDS.— Continued. 



W 
Talc 
(Soap- 
stone or 
Stea- 
tite). 
(Massive 
or rock 
constitu- 
ent.) 



Before Blowpipe, 



H 3 Mg,Si 4 19 When foliated the foliae are not elastic. Very soft, scratched by 

the finger-nail. Potstone y ordinary soapstone more or less im- 

Magnesia pure, which is coarse, granular, and is gray, grayish, or brown- 

31.7*. gray in cojor. Also fine granular, e.g., French chalk. 
Silica, Constitutes extensive beds in some regions. Also occurs in small 

63.5*. quantities in many rocks. Frequently associated with serpen- 
tine, talcose or chloritic schists, and dolomite, and contains 
crystals of a number of other minerals. 



Exfoliates before blowpipe. Mois- 
tened with cobalt solution and 
heated assumes a pale-red color. 



Mag* MgCOt. White and like calcite in appearance, but often occurring massive, Infusible, 

nesite and looking like unglazed porcelain. 

(Mas- Magnesia, This mineral forms quite extensive beds in Canada and in Greece, 

sive). 47-6*- and occurs in connection with serpentine, talcose schists and 

CO* other magnesian rocks, also gypsum, and is usually associated 

= 52.4*. with the magnesium minerals, steatite, serpentine, and dolomite. 

Also found in serpentine, or so admixed with the serpentine as 

to form a variety of verd-antique marble. 



103 



Characters. 

Treatment with Acids, etc 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 
ness. 



Sp. Gr. 



Crys- 
talli- 
zation. 



Magnetic 

BEFORE 
OR AFTER 

Heating. 



Uses. 



Not acted upon by 
acids. In closed lube 
gives a little water, 
but not till highly 
heated. 



White, apple 
to dark 
green, 
brown, 
grass- and 
black-green 
when im- 
pure. 



Pearly White Infus. 

or or 

lighter above 

than 5. 
color. 



I-I5 



2.7 



IV. or 
V. 



Steatite or soapstone is simply a 
massive form of talc, and is ap- 
plied to a great variety of pur- 
poses, but chiefly to the manu- 

factureof fire-brick, laundry, bath, 

and chemical tubs, hearthstones, mantels, pencils (French chalk), cooking- 
pots, griddles, etc. It is carved into many objects, both useful and orna- 
mental. When ground it is used as polish in the composition of mineral 
paint, in the manufacture of machinery lubricants, for skin and leather 
dressing, and as an adulterant for soap, for removing grease from cloth, etc. 
If the powder be exceedingly fine, it has the property of clinging to metal 
and stone with great tenacity, and makes the finish which protects their 
surfaces from the weather. It is said to be used with excellent results for 
heating-stoves. (See Mineral Industry \ vol. 2.) The principal use of fibrous 
talc is in filling and weighting paper, to which it gives strength, weight, dura- 
bility, and finish. Being insoluble and perfectly harmless when taken into 
the system, it is used quite extensively as an adulterant in medicines. It is 
also largely mixed with cheaper kinds of soap, and forms the basis of 
numerous fire- and water-proof paints and plasters. 



Concentrated solution 
(hot HC1) gives no 
precipitate with 

H1SO4. Compare 

dolomite, which gives 
a precipitate. Dis- 
solves entirely in 
H_SO«; the other only 
partially, but, like it, 
it effervesces with hot 
HC1, but not with cold. 



White, 
yellow, 
gray, 
brown, 


Vitre- 
ous, 
silky. 


green. 





White Infus. 3.5-4.5 3.12 



III. Besides being used for 

hearths in the " Basic" 
processes in manufacturing 
, steel as described, it is used 
quite largely as a bleaching 
agent in the manufacture of 

paper from wood-pulp and 

in the construction of portions of fire-proof 
buildings. It is also used in the manufacture 
of Epsom salts (sulphate of magnesia) and for 
other chemical purposes. 



103 



Name. 



Com p. and 
pbkcbntagk 
or Important 
constiturnt. 



Specific 



GSMKRAL CHARACTERS AND ASSOCIATIONS. 



Bbporb Blowpipe. 



MANGANESE AND ITS COMPOUNDS. 

These are readily recognized by the characteristic amethystine color oxide of manganese imparts to beads of borax and salt 
when cold. With salt of phosphorus, brown-violet when hot, pale-red violet when cold. Do not confuse with the pale violet 
bead opaque. With soda in O. F. on platinum wire, or, preferably, platinum foil, the color is green or bluish green. Most varieties 

brown hematite (limonite) and less often with varieties of red hematite or magnetite. Uses. — Over nine tenths of the 

used in the manufacture of steely since manganese imparts to the steel not only hardness, but a high degree of toughness and durability. It 
only the very pure ores are used. 



Pyrolu- 
site. 



MnO,. 

Manga- 
nese, 

632* 



Psilome- Variable, 
lane. 



The common ore. Soft and soils fingers. Distinguished by its Gives manganese reaction, 
color, softness, etc. Nodular and in layers. Compact to uncon- 
solidated, etc. 

Usually occurs in connection with psilomelane, both crystallized 
and massive. Often in connection with limonite, both being 
secondary minerals due to the leaching of the rock containing 
manganese and iron. 

Usually harder than the foregoing, with which it is often asso- Reacts for manganese. Generally 



ciated. Usually more or less admixed with barium and potas- 
sium, especially the former. Compact and usually smooth. 
Nodular, botryoidal, and mammillary, massive and stalactitic. 
Tendency, like limonite, to acicular concretionary forms. Much 
resembles above, except that it affords water, and is much harder 
and contains less manganese. 
Like the above, often associated with limonite in segregated 
masses in clay due to the decomposition of limestones and other 
rocks containing manganese and iron. 



gives barium flame, yellowish green 
when heated in forceps. 



104 



Character*. 



TREATMENT WITH AC1DS,ETC. 



Color. 



Lustre. Streak 



FUSI- 
BILITY. 



Hard- 

NESS. 



Sp.Gr. 



Crys- 
talli- 
zation. 



Magnetic 

BEFORE 
OR AFTER 

Heating. 



of phosphorus In O. F.; colorless in R. F. With borax the color becomes violet, amethystine, or purple when hot, amethystine 
color imparted to beads by presence of titanic acid, which only appears on heating in R. F. Too large a quantity renders 
are soluble in hydrochloric acid with evolution of chlorine. The oxides are frequently associated with ores of iron, especially 
manganese that is produced is used in the manufacture of the alloys of iron and manganese, known as ferromanganese or spiegeleisen, 
is used to a small extent in bleaching, and also in calico-printing, dyeing, and to give a violet color to glass and pottery, for which purposes 



HC1 dissolves it, with 
evolution of chlorine. 
No water in closed 
tube. 



Iron-black, 
dark steel- 
gray to 
bluish. 



Metal- 
lie, sub- 
metal- 
lic. 



Black, 
bluish 
black. 
Some- 
times 
shin- 
ing. 



Infus. 2.5 



4.82 



IV. 



See under heading Manga- 
nese, etc. 



In HC1 solution sul- Iron-black 
phuric acid yields to dark 
white precipitate of steel-gray, 
sulphate of baryta. 
Yields much water in 
closed tube. 



Subme- 
tallic. 



Black- 
ish to 
brown- 
black. 
Some- 
times 
shin- 
ing. 



Infus. 5-6 



4.2 



Amor- 
phous 



See under heading Manga- 
nese, etc. 



105 



Nam*. 



Coup, and 
Pbrcbntagb 
op Important 
constituent. 



Specific 



Gbneral Charactbrs and Associations. 



MANGANESE AND ITS COMPOUNDS.— Continued. 



Braun- 
ite. 



Manga- 
nite. 



Haus- 
mannite. 



Wad 
(Bog 
Manga- 
nese). 



3M113O1 Massive, and often associated with the above species. 

-f MnSiO,. 

Sometimes 

Mn s O,. 



B spore Blowpipe. 



Reacts for manganese. 



Manganese, 
63.6*. 

Mn,O a . 
H.O. 

Manga- 
nese, 

62.4*. 

Mn.Oi. 

Manganese, 
71.9* 

Variable. 
H 9 Mn a O,. 



Prismatic cleavage, sometimes perfect. Brittle. Comparatively 
rare. By loss of water it changes into pyrolusite, braunite, or 
hausmannite. 

Occurs sometimes in veins traversing porphyry and associated 
with calcite and barite. 



Rare and unimportant. 

Sometimes occurs in porphyry along with other manganese ores. 



Reacts for manganese 



Reacts for manganese. 



Earthy variety and common, but of small importance. Soft, and Reacts for manganese. 

soils fingers. Usually mixed with silica, baryta, alumina, and 

iron oxide, sometimes nickel and cobalt. Light in weight. 

Rarely hard in reniform masses. 
Occurs as a marsh deposit, and is the result of the decompositions 

of the other ores. Sometimes contains oxide of cobalt as well as oxide of copper. 

contains oxide of nickel besides the other two, with iron, lead, and sulphur, 

to 25* water. Can hardly be regarded as distinct mineral species. 



Sometimes alsol 
Usually contains from 10J 



106 



Characters. 

Treatment with Acids, btc 



Color. 



Lustre. Strbak 



Fusi- 

B1LITY. 



Hard- 
ness. 



Sp.Gr. 



Crys- 

TALLI- 
ZATIOH. 



Magnetic 

BEFORE 
OR AFTER 

Heating. 



Uses. 



Dissolves in HC1, etc., Dark 
leaving a residue of brown- 
gelatinous or floccu- black to 
lent silica. steel-gray. 



Subme- 
tallic. 



Same 
as 
color. 



Infus. 



6.5 



4-7 



II. 



See under heading Manga- 
nese, etc. 



In closed tube yields 
much water, and in 
this differs from the 
following. Otherwise 
like the above. 


Dark steel- 
gray to 
iron-black. 


Subme- 
tallic. 


Red- 
dish or 
tar- 
nished 
brown 
to 
black. 


Infus. 


4 


43 


IV. 


Gives no water in 
closed tube. 


Brown- 
black. 


Subme- 
tallic. 


Chest- 
nut- 
brown. 


Infus. 


5-5.5 


4.7 


II. 


Gives much water in 
closed tube. 


Dove-gray, 
bluish 
black, 
brown to 
black. 


Earthy, 
dull. 


Red- 
dish 
brown. 


Infus. 


Soft 
to 

rarely 
6. 




Amor- 
phous 



See under heading Manga- 
nese, etc. 



See under heading Manga- 
nese, etc. 



Sometimes used for bleach- 
ing and for umber paint. 



107 



Name. 



Com p. and 
Percentage 
ok Important 
Constituent. 



Specific 



General Characters and Associations. 



MANGANESE AND ITS COMPOUNDS.— Continued. 
MnCO.. 



Rhodo- 
chrosite 
(Carbon- 
ate of 
Manga- 
nese). 
(Dialo- 
gue.) 

Rhodo- 
nite 

(Manga- 
nese 
Spar). 
(Silicate 
of man- 
ganese.) 
Common 
vein- 
stone. 



Manga- 



47-8*. 



MnSiOt. 

Manga- 
nese, 

41.9* 



Manganspath. Usually pink or rose-red color. Often calciferous, 
ferriferous, and sometimes zinciferous. Occurs in veins with 
other metallic ores, such as those of silver, lead, or copper, or 
associated with other ores of manganese. Sometimes in strati- 
fied or bedded masses. The above oxide ores are in some cases 
resultant from the oxidation of original carbonate ore. It is 
quite largely mined in France, but is roasted and thus con- 
verted into the commercial oxide before being shipped. 

Manganese Spar. Often dark brown or black on surface, 
" through strong tendency of manganese protoxide to pass to a 
higher state of oxidation." Somewhat resembles red feldspar, 
but readily distinguished by its behavior B. B. and with acids. 
On exposure to air oxidizes rapidly, the outcrop of many 
metalliferous veins appearing black in consequence. 

Frequently found in the western United States in fissure veins and 
similar deposits in connection with and as the gangue of the 
ores of silver, lead, gold, copper, etc. 



Before Blowpipe. 



Changes color to gray or brown or 
black. Decrepitates strongly and 
gives manganese reaction. Infusi- 
ble. 



Fuses quietly at 3. Gives manganese 
reaction. When heated becomes 
dark brown. 



MEBCUHY AND ITS COMPOUNDS. 

Mercury, or quicksilver, and its amalgams volatilize on charcoal, but give a sublimate of metallic mercury when heated in 
brushed together with a feather, etc. When a gray sublimate is obtained without distinct metallic globules, the part of the tube 
case mercury exists in so small a quantity that the sublimed metal is not perceptible, it may be detected by inserting a piece of 
gold, giving it a white color. The ores follow. 



108 



CHARACTERS. 



TREATMENT WITH ACIDS.KTC. 



Color. 



LUSTRE. StRSAK 



Fusi- 

BIUTY. 



Hard- 
ness. 



Sp. Gr. 



Magnetic 

BRPORB 

„,™v, OR AFTER 

ZATION. Heat|NG . 



CRYS- 
TALLI- 



NES. 



Soluble in heated HO, 
with effervescence. 
On exposure to air 
changes to brown or 
bright rose-red; va- 
rieties become paler. 



Slightly attacked by 
HC1. Does not effer- 
vesce like preceding 
unless admixture of 
CaCOi is present. In 
powder partially dis- 
solves in HC1, the 
residue becoming 
white. 



Rose-red, 


Vitre- 


Whit 


yellowish, 


ous, 




gray, 


pearly. 




brown, 






fawn color, 






and deep 






red. 






Rose-red to 


Vitre- 


Un- 


brown. 


ous. 


col- 
ored, 



Infus. 



3*5 



III. 



See under heading Manga- 
nese, etc. 



2.5-3 



3.6 



VI. 



See under heading Manga- 
nese, etc. 



closed tube with or without soda; best with soda. The metal condenses above assay In globules on the tube. These may be 
coated with it is cut off and boiled in a test-tube with a little dilute HC1. By this treatment mercury collects in shining globules. In 
gold-leaf, held on end of iron wire, into the tube just above assay. On heating, the mercury is volatilized and unites with the 



109 



Namc 



CoMP. AND 

Percentage 
of Important 
Constituent. 



General Characters and Association*. 



MEBCUBY AND ITS (COMPOUNDS.— Continued, 

Native. Hg. • Occurs in small liquid globules, probably resultant from the follow- 

ing by some secondary reaction, scattered throughout its gangue. 
The other ores frequently contain it. 
It also sometimes occurs alloyed with silver, when it forms native 
amalgam in combination with sulphur and antimony in tetra- 
hedrite. 



Specific 



Before Blowpipe. 



Entirely volatile, going into vapor 
at 35©° C. (662 a F.). # Solidifies 
and crystallizes into octahedra at 
- 38°.8 C. (- 37°. 9 F.), when it be- 
comes soft and malleable. 



Cinna- 
bar. 



HgS. 

Mercury, 
86.2*. 



Calomel. Hg,Cl,. 

Mercury, 
84.9* 



The common ore of quicksilver. Distinguished from realgar by 
the alliaceous fumes of the latter on charcoal and other charac- 
teristics. Usually admixed with clay, iron oxide, or bitumen. 
Somewhat sectile. 

Occurs chiefly ii> veins in slate rocks, shales, and schists, both the 
most ancient and the more recent. These rocks are often meta- 
morphic, and dikes of eruptive material are usually found in close 
proximity. It is also sometimes found in, granite, sandstone, 
limestone, and porphyry. The associated minerals are pyrite, 
marcasite, sulphides of copper, stibnite, realgar, gold, etc. The 
gangue minerals are usually calcite, quartz, barite, and fluorite. 
It is usually not found in large quantities in crystalline or 
igneous rocks. 

Tough and sectile. (Rare.) 
Occurs with cinnabar. 



Entirely volatile unless admixed with 
gangue (quartz, calcite, etc., etc.). 



Volatilizes on charcoal, coating the 
coal white. 



110 



Characters. 



Treatment with Acids, etc 



Color, 



Lustre. Streak 



Fusi- 
bility. 



Hard- 



Sp. Gr. 



r Magnetic 

BEFORE 

jm?Z OR AFTER 

ZATION. Hbatihg< 



Una. 



Dissolves readily In Tin-white, 
nitric acijl. 



Mixed with soda in 
closed tube gives me- 
tallic mercury, but 
alone a black subli- 
mate. In open tube 
gives reaction for sul- 
phurous acid, and if 
carefully heated, mi- 
nute globules of me- 
tallic mercury, which 
condense on the cold 
portion of the tube. 



Red to red- 
dish brown. 
Some varie- 
ties gray or 
black, but 
streak red. 



Bril- 
liant 
metal- 
lic. 



Unme- 
tallic to 
dull 
and 
earthy; 
crystals 
ada- 
man- 
tine. 



Vol. 14.4 I. It is largely used in the ex- 
traction of gold and silver 
from their ores by amalga- 
mation, to a less degree in silvering mirrors, for thermometers and barometers, 
and for many purposes in the arts, in the laboratory, and in medicine, e.g., as 
bichloride of mercury, the best antiseptic preparation known, calomel, etc. 



Scar- 
let- 
red. 



Vol. 



2-2.5 



8.9 



III. 



The paint vermillion, which 
is used largely in printing, 
lithographing, etc., is pre- 
pared from this ore, having 
the same chemical composi- 
tion as the ore. 



In nitric solution ni- 
trate of silver gives 
heavy precipitate of 
chloride of silver. In 
closed tube volatilizes 
without fusion and 
forms white subli- 
mate. 



Gray-white, 


Ada- 


Yel- 


yellowish 


man- 


low- 


gray to 


tine. 


ish 


b-own. 




white 



Vol. 



1-2 



6.4 



II. 



Of great value in medicine. 



Ill 



Name. 



Comp. AND 

PPKCrfNTAGK 

op Important 
Constituent. 



General Characters and Associations. 



Specific 



MBBCTJBY AND ITS COMPOUNDS.— Continued, 

HgTe. Rare. Found sparingly in Colorado with gold tellurides. Massive, 

granular. 
Mercury, 

61.5* 



Colora- 
doite 
(Mer- 
cury 
Tellu- 
ride). 



Mica Various. Foliated. Very elastic, and is susceptible of being separated into 

(Musco- K,Al t Si,O t . a great number of very thin sheets. Physical characters readily 

vite). recognized. Folia tougher and harder than those of talc or 

(Isin- chlorite. The latter are non-elastic. Sometimes in large plates, 

glass.) when it possesses considerable value and is extensively mined. 

Common It is a very common mineral, and is one of the essential constitu- 

rock ents of ordinary granite. It is found in most granites and 

con- . gneisses, and in dikes of coarse granite traversing a granitic 

stituent. country rock, or in gneiss, mica schist, porphyritic granite, 

etc.; sometimes in granular limestone. The variety known as 

amber mica or black mica, which is common in Canada, is biotite 

or magnesium iron mica. This is usually highly colored by 

oxide of iron, and this variety supplies nearly the total supply 

of commerce where transparency is not required. See Uses. 

Usually associated with such minerals as quartz, feldspar, beryl, 

tourmaline, garnet, columbite, and samarskite. Cassiterite is 

the associated mineral in the Black Hills, S. D., and apatite is 

found in connection with the mica deposits in Canada. It is not 

uncommon in sedimentary rocks such as micaceous sandstones, 

grits, shales, etc. 



Before Blowpipe. 



In tube decrepitates, fuses, and yields 
metallic mercury, as well as drops 
of tellurium dioxide. 



B. B. fuses with difficulty on edges of 
very thin scales to a gray or yellow 
glass. 



11* 



Characters. 

Treatment with Acids, etc. 



Color. 



Lustre. Streak 



Fusi- 

BIUTY. 



Hard- 

NB88. 



Sf. Git. 



Crys- 
talli- 
zation. 



Magnetic 
before 

OR AFTER 

Heating. 



Uses. 



Soluble in nitric acid. Grayish Metal- Gray- 

black or lie. ish. 

iron-black. 



Vol. 



8.6 



Amor- 
phous 



See under heading Mercury, 
etc. 



Not acted upon by 
acids. In closed tube 
yields water. 



Colorless, 


Pearly, 


White 


Above 


white, 


trans- 


orun- 


5- 


gray. 


parent 


col- 




brown, 


to 


ored. 




yellow, red, 


trans- 






and green. 


lucent. 







2-2.5 



2.8 



IV. 



Mica was formerly used in 
Siberia as a constituent for 
glass in window's, whence it 
has been called Muscovy 
glass. It is in common use 
in lanterns, for the doors of 
stoves and furnaces, and 
other like purposes where a 
transparent substance not 
easily affected by heat is de- 
sirable. When pulverized it 
is used in the manufacture of 
wall-paper in order to give a 
glistening effect. The con- 
sumption of mica is increas- 
ing largely at the present 
time, owing to the fact that 
usually when more or less 
finely ground it finds many 
uses in electrical appliances, 
being an excellent noncon- 
ductor and insulator. 



113 



Name. 



Com p. and 
Percentage 
of Important 
constituent. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



MOLYBDENUM AND ITS COMPOUNDS, 

With borax bead in O. F. colorless when hot; faint yellow when cold. With saturation the bead becomes in R. F. an opaque 
certain chemical operations and analytical work, e.g., in the detection of phosphoric acid, etc. 



Molyb- MoSj. Very soft and sectile. Soils fingers or paper like graphite (a. v.), 

denite. and looks much like it. Laminae very flexible, but not elastic. 

Molybde- Occurs in granite, gneiss, syenite, mica schist, and other allied 
num, bo%. crystalline rocks; also in granular limestone, either imbedded in 
the rock or disseminated through it. Usually associated with 
scheelite and apatite, and sometimes with zircon. 



In forceps colors flame light green or 
yellowish green, which readily dis- 
tinguishes it from graphite. This 
effect is assisted if it is first moist- 
ened with H 9 SO«. 



Molyb- 


PbMoO*. 


date of 




Lead 

(Wulfen- 

ite). 


Molybde- 
num, 

26.25*. 


Mona- 
zite. 


Phosphate 
of the ce- 




rium 




metals, 




essentially 
(Ce.La.Di) 
PO*. 




Variable;. 
(See Da- 




na's Min.) 



Heated on platinum-foil with drops of strong sulphuric acid until 
copious fumes escape and allowed to cool, then breathed upon, 
acquires an ultramarine-blue color. Brittle. Occurs with other 
ores of lead, but is rare and unimportant. 

Sometimes associated with vanadinite, pyromorphite, etc., upon 
crystalline limestone. 

Found in the form of sand, and being sometimes distributed quite 
abundantly as an accessory constituent of gneissoid rocks in cer- 
tain regions. Found as rounded grains of sand in gold-wash- 
ings, as in North Carolina and Brazil. Sometimes known as 
thorium sands. As its name signifies, it is a rare mineral. 



Decrepitates and fuses below 2. With 
metallic lead; with salt of phos- 
a yellowish-green glass, which in 
green with black flocks. Solution 
if diluted with water, and upon 
zinc and agitated, becomes blue. 

Infusible, turns gray, and when 
moistened with sulphuric acid 
colors the flame green. With borax 
gives a yellow bead when hot and 
colorless on cooling. A saturated 
bead becomes enamel-white on 
flaming. (Dana.) 



114 



Characters. 



Treatment with Acids, etc 



Color. Lustre. 



Streak 



Fusi- 
bility. 



Hard. 



Sp. Gr. 



Crys- 
talli- 
sation. 



Magnetic 

BEFORE 
OR AFTER 

Heating. 



Uses. 



black or bluish to green enamel when cold.- 



- Uses. — *While the supply is quite limited, the salts of molybdenum are very useful in 



Heated in platinum 
spoon with nitre ex- 
plodes, with evolution 
of light and heat. In 
open tube sulphurous 
fumes and a pale yel- 
low sublimate. 

soda on charcoal yields 
phorus in O. F. gives 
R. F. becomes dark 
in HC1 greenish, which, 
' addition of tin-foil or 



Lead-gray 
to blackish. 



White, red, 
gray-green, 
but gener- 
ally yellow- 
ish. 



Metal- 
lic, 



Resin- 
ous or 
ada- 
man- 
tine. 



Lead- 
gray 
or 

green- 
ish. 



Infus. 1-1.5 4.8 



III. 



White 1-1.5 



6.9 



II. 



See under heading Molybde- 
num, etc. 



See under heading Molybde- 
num, etc. 



Soluble with difficulty 
in HC1. 



Hyacinth- 
red, clove* 
brown, 
reddish or 
yellowish 
brown. 



Inclin- 
ing to 
resin- 
ous. 
Sub- 
trans- 
parent 
to sub* 
trans- 
ucent* 



Whit- 
ish or 
same 
as 
color. 



Infus. 5-5.5 5-52 



V 



The chief use of this mineral 
is in the manufacture of 
cylindrical hoods or man- 
tles used in the Welsbach 
light. (See Rep. U. S. 
Geol. Sur. 1894-95, Part IV., 
Min. Res.) 



115 



Name. 


Coup. AND 

PERCENTAGE 

of Important 

CONSTITUBNT. 


NICKEL AND ITS 


Genthite. 
Impure 
vari- 
eties — 
Garnier- 


H f (Ni,Mg) 4 

Variable. 
See de- 


ite, etc. 

Noume- 

ite. 


scription. 


Emerald 
Nickel 
(Zara- 
tite). 
(Nickel 
Carbon- 
ate.) 


3 NiO,CO, 
+ 6H,0. 

Nickel, 

46.7* 


Pentland- 
ite. 


(Fe,Ni)S. 
Nickel, 




39-9*- 



Specific 



Gbnbkal Characters and Association*. 



Bbforb Blowpipe. 



COMPO u n uS.— Continued. 

The large supply from New Caledonia is derived from garnierite, 

which is pale green and adhesive to the tongue, and noumeite, 

which is dark green and unctuous. These ores, which are hy- 

drated silicates of magnesium and nickel, are amorphous, soft, 

and friable, have a dull lustre, and vary from bright apple-green 

in color to nearly white. 
Found in veins in decomposed rocks of eruptive origin, among 

which serpentine is the most important. The New Caledonia ore, as exported for treatment, averages! 

7% to 10* nickel. It is frequently associated with chrome iron ore and oxide of cobalt. It is sometimes' 

found in talcose schist and associated with phosphate of nickel. 



Reacts for nickel. In O. F. with 
borax, violet bead becoming red- 
brown on cooling, which bead, 
when treated in R. F., becomes 
gray from reduced nickel. 



Incrusting, aiso massive, compact, minutely mammillated, and 

stalactitic. 
Usually containing variable quantities of sulphur, associated with 

chromic iron, cobalt ores, and magnetite in serpentine rocks. 



Sulphides of iron and nickel. Has an uneven fracture and an 
octahedral cleavage. Not magnetic, and is brittle. 

Sudbury, Ont., etc., where also an ore which corresponds generally 
to NiiFeS* is found. The usual ore of the Sudbury district is a 
mixture of chalcopyrite and nickeliferous pyrrhotite, the per- 
centage of nickel in the latter varying from 1% to 3* (Min, Ind.). 
See supra. 

Usually occurs in close association with chalcopyrite. 



Becomes magnetic, and gives 
nickel reaction with borax. 



the 



Roasted on charcoal gives with fluxes 
reactions for nickel and iron. 



113 



Characters. 



TSBATM INT WITH ACIDS, BTC. 



COLOR. 



Lustre. Streak 



Fwsi- 

B1L1TY. 



Harb- 



Sf.Gr. 



Crts- 

TALLI- 
ZATIOK. 



Magnetic 

BBFORB 
OR AFTSR 
H BATING. 



Uses. 



In closed tube black- 
ens, and gives much 
water. Decomposed 
by HC1 without gela- 
tinizing. 



Apple to 
emerald 
green, and 
sometimes 
yellowish. 



Resin- 
ous. 



Green- 
ish 
white. 



Infus. 



3-4 



2.5 



Amor- After, 
phous 



See under heading Nickel, 
etc. 



Soluble In heated 
dilute HCl, with effer- 
vescence. Gives in 
closed tube a large 
amount of water, and 
blackens and leaves 
grayish-black mag- 
netic residue. 

Yields • sulphurous 
fumes in the open 
tube. 



Emerald- 


Vitre- 


Paler 


Infus. 


green. 


ous, 
trans- 
parent 
to 

trans- 
lucent. 


than 
color. 




Light 
bronze- 

vellnw. 


Metal- 
lic. 


Light 
bronze- 
brown. 


TEasily 



2.6 



Amor- After, 
phous 



See under heading Nickel, 
etc. 



3.5-4 



4.6 



I. 



See under heading Nickel, 
etc. 



119 



Name. 



CoMP. AND 

Percentage 
of Important 
Constituent. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



NICKEL AND ITS COMPOUNDS.— Continued. 

Millerite NiS. Usually in capillary needle-like crystallizations. Sometimes like 

(Capil- wool. Fibrous; also in fibrous crusts. Brittle, capillary crystals 

lary Nickel, elastic. 

Pyrites). 64.6*. Found with calcite, dolomite, fluorite and ankerite in cavities in 

(Nickel hematite, and also with pyrrhotite. Also found with niccolite, 

Blende.) nickeliferous iron pyrites, chalcopyrite, etc. 



Roasted mineral reacts for nickel as 
above. On charcoal in R. F. 
roasted mineral gives a coherent 
mass, which is attractable by the 
magnet. 



Nickel- (See Iron Ores and above.) This frequently contains from 1% to as much as 5* of nickel, and when it does is a valuable 

iferous Ont., etc. See above. The mines of this district are in Huronian rocks (gneiss and red quartz syenite), and yield, 

Iron and the rare mineral sperrylite (arsenide of platinum), q. v. 
Pyrites. 



Ullman- 


NiSbS. 


nite. 






Nickel, 




27.8*. 




Antimony, 




57* 


Nickel 


NiSAs. 


Glance 




(Gers- 


Nickel, 


dorffite). 


35.4*. 




Arsenic, 




45-3*- 



Brittle and cubic cleavage. Fracture uneven. 



After long heating becomes magnetic. 
Easily fusible, and reacts for anti- 
mony, arsenic, and nickel. On char- 
coal fuses to globules, boils and 
coats coal white. 



Brittle, with uneven fracture. Nickel often replaced by iron or by In a closed tube decrepitates violently 
cobalt to considerable extent. and gives yellowish-brown subli- 

mate. On charcoal gives arsenic 
reaction. 



120 



Characters. 



Treatment with Acids, etc 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 

NESS. 



Sr. Gr. 



Crys- 
talli- 
zation. 



Magnetic 

before 

or after 

Heating. 



Uses. 



Gives no sulphur in 


Brass-yel- 


Metal- 


closed tube: in open 


low inclin- 


lic, often 


tube, sulphurous 


ing to 


gray iri- 


fumes. 


bronze- 


des- 




yellow. 


cent 
tarnish. 



Bright 
green- 
ish 
black 



Easily 3.5 56 HI. After. 



See under heading Nickel, 
etc. 



ore. Magnetic iron pyrites (pyrrhotite) especially is frequently nickeliferous— Sudbury, 
in addition to pyrrhotite, considerable quantities of ckalcopyrite (copper from 1* to 4%), 



After. 



See under heading Nickel, 
etc. 



HC1 has little effect, 
but nitric acid or aqua 
regia dissolves it, with 
separation of sulphur. 



Steel-gray 


Metal- 


Gray- 


to silver- 


lic. 


ish 


white. 




black. 



5.5 



e.3 



After. 



See under heading Nickel, 
etc. 



Dilute nitric solution, 
with chloride of ba- 
rium added, gives 
heavy precipitate. 
Aqua regia solution 
same as copper nickel. 



Silver-white 
to steel- 
gray and 
grayish 
black. 



Metal- 
lic. 



Gray- 
black. 



Easily 5.5 



After. 



See under heading Nickel, 
etc. 



121 



Name. 



Com p. and 
Percentage 
of Important 
Constituent. 



Specific 



General Characters and Associations. 



NICKEL AND ITS COMPOUNDS.— Continued. 



Nickel 
Ochre 
(Nickel 
Ar- 
senic). 
(Anna- 
bergite.) 

Nitre 

(Com- 
mon 
Salt- 
petre). 



Ni,As,0» 

+8H,0. 

Nickel. 

29-4*, 
Arsenic, 

26.6*. 

KNO,. 



Soft, earthy, and apple-green in color. Fracture uneven or 
earthy. With soda on charcoal easily reduced to small, brilliant 
metallic particles, which are highly magnetic. Probably due to 
decomposition of niccolite, etc. 



Potassium nitrate or potash nitre. Brittle, with uneven fracture. 
Occurs usually as needle-form crystals and crusts on surface of 
earth, rocks, and in caves, etc. Spain, Egypt, Persia, and large 
quantities from India. 



Before Blowpipe. 



On charcoal fuses in R. F. with emis- 
sion of arsenical vapor to blackish- 
gray globule, which reacts for 
nickel with borax. Always con- 
tains a little cobalt, which will 
usually give a blue bead with 
borax. 

On charcoal deflagrates strongly and 
detonates with combustible sub- 
stances. Fused on platinum wire 
colors flame violet. 



Variety* 
Chile 
salt- 
petre. 



NaNO, 



Sodium nitrate or soda nitre. Somewhat sectile. Deliquescent. 
Taste cooling. Double refraction in crystals. Occurs granular 
or massive, and forms beds (caliche) in the Pampa de Tamarugal 
and elsewhere in Chile, but is found also in small quantities in 
Nevada and California. Usually associated with large quanti- 
ties of common salt, gypsum, and other impurities. Iodine is 
usually present in minute quantities, nevertheless a very large 
proportion of the supply of commerce is drawn from this source. 
See Min. Ind. % Vol. II. 345. 

12S 



Deflagrates less violently than potash 
nitre, causing yellow light. Colors 
flame intensely yellow. (Sodium.) 



Char act* *s. 

Tebatmbnt with Acids,etc. 



Color. 



Lustrb. 



Strsak 



Pusi- 

B1UTY. 



Hard- 

MBSS. 



Sp. Gr. 



Magnbtic 

BBFORB 

, 1Tinu OR AFTER 

ZATION. Heat|nu 



Crys- 

TALLI- 



USBS. 



The HC1 and nitric so- 
lutions have a green 
color. Excess of am- 
monia colors this sap- 
phire-blue. 



Apple- 
green. 



Earthy. Green- Easily Soft, 
white. 



After. 



See under heading Nickel, 
etc. 



Easily soluble in wa- 
ter. In solution bi- 
chloride of platinum 
produces a yellow 
crystalline precipi- 
tate, especially if 
stirred with a glass 
rod for a few minutes. 
Not altered by expos- 
ure. Taste saline and 
cooling. 

Dissolves in three 
parts of water at 6o° 
F. Is strongly deli- 
quescent. Bichloride 
of platinum produces 
no precipitate, thus 
distinguishing it from 
potassium nitrate. 



White. 



Vitre- 
ous, 
sub- 
trans- 
parent. 



White Easily 



IV. 



White, gray, 


Vitre- 


Whit- 


yellowish, 


ous, 


ish, 


orange, 


trans- 


or 


reddish 


parent 


paler 


brown, 


to sub- 


than 


and lemon- 


trans- 


color. 


yellow. 


lucent. 





Easily 



1.5-2 2.25 



III. 



Nitre is largely employed in 
the manufacture of gun- 
powder and nitric acid. It 
is also used in medicine, in 
metallurgy, and in chemis- 
try, as a powerful oxidizing 
agent, etc.; to a certain ex- 
tent for pyrotechnic pur- 
poses and fulminating pow- 
ders. 



This is used to a certain ex- 
tent in the manufacture of 
gunpowder, for which pur- 



123 



pose it must be first converted into nitre (nitrate 
of potash), and also in the manufacture of nitric 
acid, etc. There is a very large and steady 
demand for Chile saltpetre for use in the prepa- 
ration of fertilizers throughout Europe, which 
purpose consumes most of the production. 



Name. 



Obsidian 
(Vol- 
canic 
glass). 



COMP. AND 

Percbntags 
or Important 
Constituent. 

Variable. 



Gbnkral Characters and Associations. 



All the varieties are amorphous, volcanic products, and are not 
homogeneous. True obsidian is characterized by intense vitre- 
ous lustre, and contains about 70* to 75* silica, and has essen- 
tially the same constitution as rhyolite. 

Occurs in connection with trachytic and more especially rhyolitic 
outflows. Sometimes occurs as independent sheets or dikes, but 
more often on the surface of crystallized lava-sheets or on the 
outer portions of dikes. (Kemp.) 

Variety: Pumice. This is finely scoriaceous with linear cells, 
and contains 70* to 78* of silica. (Dana.) It is characterized 
by a vesicular froth-like structure. Pumice is associated with 
obsidian. 



Spbcific 



Before Blowpipe. 



Fuses with swelling up, at 3.5-4, to a 
vesicular white glass or enamel. 



Opal. SiO«.«H t O. Composed of silica like quartz, but the true nature of the opal 

condition of silica is not very clearly understood, but is believed 
Water . to be one of lower degrees of hardness and specific gravity, 

variable, Small quantities of iron oxide, alumina, lime, magnesia, and the 

and some- alkalies are often present, as well as quartz. Exhibits rich play 
times of internal reflections and opalescence, the colors often blending 

regarded and changing according to the direction in which the stone is 

as non- held. It differs from quartz in its lustre and in the total absence 

essential. of crystalline structure. It occurs massive, sometimes small 

' reniform, stalactitic, or large tuberose. (Dana.) It is found 
usually in cavities or fissures and seams in igneous rocks — 
. .».• usually trachyte and porphyry — also in some metallic veins. It 

is sometimes found imbedded like flint in limestone or in argilla- 
ceous beds. Widely distributed. Fine specimens found in Hun- 
gary, Moravia, Silesia, Saxony, Honduras, etc. The so-called 
fare opal of Mexico is widely distributed throughout Mexico. 



Infusible, but becomes opaque. Some 
varieties containing iron oxide turn 
red. With soda fuses with effer- 
vescence to a clear glass. 



124 



Characters. 



Treatment with Acids, etc. 



Color. 



Various, 
gray, dull 
greenish, 
purplish to 
red, brown, 
and black. 



Lustrb. Streak 

Intense 
vitre- 
ous. 



Fusi- 
bility. 



3.5-4 



Hard, 
mess. 



Sp. Gx. 



2.2-2.8 



Magnetic 

BEFORE 
,. TIOM OR AFTER 



Crvs- 

TALLI- 



Amor- 
phous 



Uses. 



Pumice is used as a powder 
for polishing ivory, wood, 
marble, metals, glass, skins, 
parchment, etc. 



Soluble in hydrofluoric 
acid rather more read- 
ily than quartz. Most- 
ly soluble in caustic 
potassa. Hydrated 
silica is precipitated 
by addition of suf- 
ficient chloride of 
ammonia. 



Colorless, 


Vitre- 


milky- 


ous, 


white, yel- 


sub vit- 


low, brown, 


reous, 


red, bluish 


resin- 


green, and 


ous, 


dark gray- 


some- 


ish green. 


times 




pearly. 




Trans- 




parent 




to 




nearly 




opaque. 



White Infus. 5.5-6.5 2-2.3 



Amor- 
phous 



When displaying brilliant 
and changing colors used 
as a gem. 




125 



Name, 



Com p. and 
Percentage 
or Important 
Constituent. 



General Characters and Associations. 



Before Blowpipe. 



PHOSPHATE BOCK. 

Mineral variety, apatite, which see. Common variety is often probably replacement of CaCO* by phosphate of lime; also 
Floridite, etc.) or as water- worn fragments, probably derived from this material, or sometimes as concretionary masses (phos- 
nodules, and furnish a large portion of the commercial supply. The substance examined for phosphorus is mixed with soda, as 
dropped into it. Then the mixed soda and substance is added so as to cover the magnesium. Heat to full fusion the contents of 
characteristic odor of hydrogen phosphide is evolved. (Do not have too much water in vessel, and see that end of tube is broken.) 
to nitric acid solution. An abundant bright yellow precipitate (phosphomolybdate of ammonium) indicates character of the 
f j, chiefly in the preparation of commercial fertilizers, and to a very much smaller extent in the manufacture of phosphorus for 
converted into soluble phosphate* or superphosphate % by being ground up and mixed with sulphuric acid before it is available as a 
from certain impurities \ such as iron oxide \ alumina , etc. Most of the Florida rock contains from 60* to 80* of lime phosphate. (See 



PLATI- Pt (Ir, Usually in flattened or angular grains, or irregular masses. 

NUM. Rh, Pd, Sometimes slightly magnetic, malleable, and ductile. Usually 

Fe). alloyed with iron, rhodium, iridium, osmium, and copper. Prin- 

Native. cipal supply obtained from placer deposits. 

Pt = from The commonly associated minerals in such alluvial deposits are, 
50* to 86*. besides quartzose pebbles and sand, magnetic iron sand, gold, 
iridosmine, topaz, epidote, chromite, garnet, and occasionally 
zircon, ilmenite, serpentine, chrysolite, peridote, diamond, etc., 
Palladium is also rarely found in such deposits. It is rarely 
found in situ, but has been reported to have been so found 
in a ferruginous feldspathic rock with iridosmine in New South 
Wales; also in grains in auriferous veins in Brazil, and oc- 
casionally in Russia. 



Infusible except before oxyhydrogen 
blowpipe. 



128 



Characters. 



Treatment with Acids, etc 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 
mess. 



Sp. Gr. 



Crys- Magnetic 

talu- bbfor * 

Jr±"" or after 

ZATION - Heating. 



Uses. 



includes fossil bones, fossil excrements (coprolites), etc. Occurs massive or in irregular superficial beds (hard rock phosphate— 
phorite) in river-beds, and usually in stratified marly sediments. Carolinas, Florida, etc. These are referred to as phosphate 
for sulphur (3 soda, 1 substance). A thin glass tube closed at one end has a piece of magnesium wire or ribbon one-half inch long 
the tube until the glass is attacked. While still red plunge under water in a small vessel, and immediately apply the nose. The 
The above test is not delicate enough for minute quantities, as in Bessemer iron ores. Best test is to add molybdate of ammonium 

specimen. Uses . — All the varieties — hard rock, soft rock, land pebble, and river pebble — are used for the same purposes, that 

making matches, etc. Very large deposits in the southeastern United States furnish great quantities of this material, which must be 
fertilizer. To be commercially valuable the rock or pebble should contain upwards of %o% of phosphate of lime and be reasonably free 
Apatite.) 



Soluble only in aqua Steel-gray 


Metal- 


Light 


regia. to whitish, 


lie. 


gray. 


rarely 




Like 


black. 




color. 



Infus. 4-4.5 16-19 



I. After, A great part of the platinum 
slightly. produced is made into va- 
rious chemical utensils, such 
as crucibles, wire, etc. To 
the chemist it is an invalu- 
able metal. It is also cm- 
ployed by balance-makers 



for weights, etc., to a small extent for 
philosophical and surgical instruments, 
and in dentistry. Very considerable 
quantities of it are used in electrical 
appliances. Somewhat used in jewelry, 
in photography, in the manufacture 
of non-magnetic watches, for coating 
copper and brass, giving a steel-lustre 
to porcelain, and for other purposes. 



127 



Nams. 



Sperry- 
lite. 



Com p. and 
Percentage 
or Important 

CONSTITUENT. 

PtAs,. 

Pt = 56.5*. 



Specific 



General Characters and Associations. 



Brittle. Occurs in minute crystals or as scales. In nickeliferous 
iron sulphide (pyrrhotite) or associated with pyrite, chalcopyrite, 
cassiterite, and as a loose material in small pockets in the de- 
composed ore, near Sudbury, Ont. (See Nickel ores.) 



Before Blowpipe. 



Decrepitates slightly. When dropped 
on red hot- platinum-foil instantly 
melts. Gives off inodorless white 
fumes of arsenic, and porous ex- 
crescences which resemble it in 
color are formed on the foil. 



Pyroz- Variable. Much the same composition as hornblende, which it closely re- 

ene sembles. Sometimes fibrous. Chief varieties are: (a) white 

(Augite). augite; (6) green augite; and (c) hypersthene, diallage, bronzite, 

Common etc. Massive and disseminated. 

rock Common in crystalline limestones and dolomite, in serpentine and 

constitu- in volcanic rocks. Occurs less abundantly in granites and meta- 

ent (of morphic rocks. Sometimes, however, forms large veins or 

eruptive beds, or interbedded masses, especially in the older and highly 

rocks es- metamorphosed rocks, 
pecially). 



Light-colored varieties fuse to a 
white glass, while the darker va- 
rieties give a black glass. 



138 



Characters. 

Trratmbhtwith Acids, etc. 

In open tube gives ar- 
senic sublimate. Does 
not fuse if slowly 
roasted, but if rapidly 
heated melts easily 
after part of its ar- 
senic has been driven 
off. In closed tube 
unchanged. 



Color. 



Tin-white. 



Lustre. Streak 



Fusi- 
bility. 



Bril- Black As de- 

liant, scribe 

metal- 
lic. 



Hard- 
ness. 



6-7 



Sp. Gr. 



10.6 



Crys- 
talli- 
zation. 

I. 



Magnetic 
before 

OR AFTER 

Heating. 



Uses. 



See under heading Plati- 
num, etc. 



Most varieties are in- 


All colors, 


Vitre- 


White 


soluble in acids. 


usually 


ous, in* 


to 




black, 


clining 


gray 




green, and 


to 


and 




greenish- 


resin- 


gray- 




black. 


ous 


ish 






and 


green. 






pearly. 





2-5 



5-5 



3-5 



V. 



Iron va- 
• rieties 
after. 



139 



Name. 



Ruby. 



Rutile. 



Sap- 
phire. 



Comp. AND 
Percentage 
of Important 
Constituent. 

Al.O,. 

Oxygen, 

Alumina, 
52.9* 



TiO,. 

Titanic 
acid, with 
usually a 
little iron. 

Ti = 6c*. 



Al a O«. 

Oxygen, 

47.1^. 
Alumina, 

$2-9* 



Specific 



General Characters and Associations. 



The gems ruby and sapphire are varieties of corundum, q. v. 
They are simply the purer kinds of fine colors, which are trans- 
parent to translucent, and are useful as gems. The well-known 
red color of ruby is its distinguishing characteristic. Usually 
occurs in place in crystalline limestone, also in gneiss, granite, 
mica slate, chlorite slate, etc., or in the soil derived from their 
decomposition, and in what is known as gem-bearing gravel. 
The best rubies come from Upper Burma, north of Mandalay. 

The associated minerals are of great variety, and usually include 
some species of the chlorite group. Differs from sapphire only 
in its color. 

Somewhat resembles tin ore, q. v. 

Frequently met with as a rock constituent in granite, gneiss, mica 
slate, and syenitic rocks, and sometimes in granular limestones 
and dolomite; frequently as secondary product in many slates. 
Sometimes found as grains or fragments in auriferous and other 
sands. Often associated with hematite, tremolite, chalcopyrite, 
tourmaline, etc. 



A variety of corundum, q. v. Quite widely distributed. Found 
associated with ruby in the Himalaya Mountains. Also found 
in Ceylon, in the Rocky Mountains, and in California. Some- 
times found in diamond gravels in New South Wales. Compare 
ruby (q. v.), of which it has the same composition and much re- 
sembles, excepting in the matter of color. 



Before Blowpipe, 



Unaltered. Dissolves slowly in 
borax and salt of phosphorus to a 
clear glass, which is colorless when 
free from iron. It is not acted 
upon by soda. 



Alone infusible, but with salt of phos- 
phorus gives a hyacinth-red or 
colorless bead, which becomes violet 
on cooling, but brownish red if iron 
is present, as is usually the case. 
Violet color best produced by re- 
ducing bead on charcoal with me- 
tallic tin. Distinguished from tin 
ore by not affording tin with soda. 

Unaltered. Dissolves slowly in borax 
and salt of phosphorus to a clear 
glass, which is colorless when free 
from iron. It is not acted upon by 
soda. 



130 



Characters. 

Treatment with Acids.etc. 

Unacted upon by acids, 
but converted into 
a soluble compound 
when fused with po- 
tassium bisulphate. 



Color. 



Red. 



Lustre. 


Streak 


Fusi- 
bility. 


Hard- 
ness. 


Vitre- 
ous. 
Trans- 


Un- 
col- 
ored. 


Infus. 


9 


parent 
to 








trans- 
lucent. 









Sp. Or. 



Magnetic 
before 
~.~.„» OR after 

ZATION. HBAT1HG> 



Crys- 

TALLI- 



3.9-4. X III. 



Uses. 



The most highly prized of 
all gems. 



Insoluble in acids 
alone, but fused with 
soda or with bisul- 
phate of potash, dis- 
solved in HC1 and 
boiled with tin, the 
solution becomes vio- 
let (titanic acid). 



Red, red- 


Ada- 


Pale 


brown, 


man- 


brown 


yellow, 


tine, 




black. 


metal- 
lic. 





Infus. 6.5 4.2 



II. When Rutile is employed for paint- 
ferrif- ing on porcelain, and quite 
erous, largely for giving the re- 
slightly quisite shade of color and 
after. enamel appearance to arti- 

ficial teeth. Some kinds 
make fine though nearly 
opaque gems. 



Unacted upon by acids, 
but converted into 
a soluble compound 
when fused with po- 
tassium bisulphate. 



Blue. 



Vitre- 


Un- 


ous. 


col- 


Trans* 


ored. 


parent 




to 




trans- 




lucent. 





Infus. 



3.9-4.1 III. 



The purer kinds of fine color 
valuable as gems. 



131 



Name. 



Silica 
(Quartz). 
Most 
common 
vein 
stone 
and rock 
con- 
stituent. 



Com p. and 
Percentage 
of Important 
Constituent. 

SiO«. 



Specific 



General Characters and Associations. 



Fracture conchoidal to subconchoidal, and uneven to splintery. 
Brittle to tough. Rock crystal, amethyst, chalcedony, agate, 
banded onyx, jasper, flint, silicious sinter, petrified (agatized or 
jasperized) wood, etc., are varieties. Most sandstones are 
almost entirely made up of an aggregation of small rounded 
grains of quartz, while it enters very largely into the composi- 
tion of most other rocks; e.g., common granite is composed of 
the three minerals quartz, feldspar, and mica. 

Note. — The so-called Mexican onyx is not true onyx, but is calcite 
usually more or less impure. (See Calcite.) 

The most common of all rock constituents, and is abundantly met 
with as such and as a vein stone. 



Before Blowpipe. 



Infusible and unaltered alone. With 
small quantity of soda fuses, owing 
to the liberation of CO», or dis- 
solves with effervescence to a clear 
glass (when pure). Unacted on by 
salt of phosphorus, and with borax 
dissolves slowly to a clear glass. 



SILVER AXTC) ITS COMPOUNDS. 

Silver compounds when fused with soda on charcoal yield a hard, white, malleable button, usually without any incrustation 
with volatile and easily oxidizable metals, it may be separated by heating on charcoal in O. F., but if associated with large 
white precipitate of AgCl. which is insoluble in boiling nitric acid, but readily soluble in ammonia. The color of the precipitate 
plate, jewelry \ and ornamental objects % and as a money metal. It is also largely used in photography ', for numerous chemical preparations \ 



Native. Ag. Eminently sectile, ductile, and malleable. Sometimes fibrous 

(" wire " silver), but often massive or in thin sheets or films 
associated with other ores of silver. Also disseminated, often 
invisibly, along with other metallic ores. 
Sometimes associated with native copper and galena. It is doubt- 
less often a secondary product from the ores of silver, and is 
found accompanying almost all the ores of silver, more fre- 
quently the sulphides, sulpho-salts, and chlorides. Occurs in 
both eruptive and sedimentary rocks. 



Fuses to white globule, which in O. F. 
gives a faint dark-red coating of 
silver oxide. Crystallizes on cool- 
ing. 



132 



Characters. 

Treatment with Acids, etc. 



Color. 



Lustre. Streak 



Fusi- 



Un affected by hydro- Colorless if Vitre- White Infus. 
chloric or nitric acid. 
Soluble only in hydro- 
fluoric acid. Dissolves 
in alkaline solutions. 



pure and 


ous to 


or 


usually 


greasy. 


paler 


whitish; 


Splen- 


than 


often 


dent, to 


color. 


smoky, yel- 


dull. 




low, red, 


Trans- 




black, and 


parent 




other 


to 




shades of 


opaque. 




color. 







Hard- 
ness. 



Sp. Gr. 



2.6 



Magnetic 
before 

,.t..™ OR AFTER 

ZATION. Hbatihg# 



Crys- 

TALU- 



III. 



Uses. 



Quartz or silica has a number 

of uses in the industries, 

.especially in the pure state. 



It is largely used in the manufacture of glass, for which pur- 
pose pure quartz sand is frequently used, though the massive 
mineral when pulverized and when not impure is equally well 
adapted. It is also used in the manufacture of pottery, of cer- 
tain filters, and for many other purposes where silica in a com- 
paratively pure state may be required, especially in an admix- 
ture with other substances. When very pure and transparent, 
sometimes used in the manufacture of eyeglasses, or optical 
instruments. Chalcedony, jasper, silicified wood, etc., are often 
carved into ornamental objects. 



on the coal, but when treated for a long time with the reducing flame a slight dark-red coating is produced. When associated 
quantities of lead or bismuth it is best to subject it to cupellation. (See Appendix.) HC1 gives in a solution of silver a heavy 

changes to slate-purple by exposure to light. This is a distinguishing characteristic. Uses. — Silver is principally used for 

in the manufacture of indelible ink, fulminating powder % etc. 



Soluble in nitric acid. 
The dilute solution, 
upon addition of HC1 
(or common salt) gives 
a white precipitate, 
which becomes violet- 
gray on exposure to 
light. Copper plate 
immersed in nitric solution is coated] 
with silver. 1 



Silver-white 
(often tar- 
nished, 
when it is 


Metal- 
lic. 


Silver- 
white 
and 
shin- 
ing. 


Easily, 
1050° 
C. 


gray to 
black). 







2.8 



10.5 

when 
pure. 



I. 



See under heading Silver, 
etc. 



133 



Name. 



COMP. AND 

Pbkckntagb 
op Important 
Constituent. 



Specific 



General Characters and Associations. 



SILVER AND ITS COMPOUNDS.— Continued. 



Silver 
Glance, 
Argentite 
(Sulphide 
or Sul- 
phuret 
(O. S.) of 
Silver). 

Brittle 
Silver 
(Steph- 
anite). 
Kindred 
anti- 
monial 
and ar- 
senical 
ores are: 



Ag.S. 

Silver, 

87.1*. 



Ag»SbS 4 , 



Silver. 



68.5*. 



Before Blowpipe. 



Can be cut with a knife like lead when massive, but it is usually 
finely disseminated through the vein material. This is probably 
the most common ore of silver. 

Occurs abundantly with stephanite, native gold, also native silver 
and copper. 



Brittle, with an uneven fracture. Occurs in veins, etc., with other 
silver ores. 

Note. — A variety is dyscrasite (AgtSb), but its composition is varia- 
ble. The following antimonial and arsenical silver ores pass 
readily one into another by almost insensible gradations, and 
the analyses of them often vary very widely, owing to presence 
of impurities. 



On charcoal in O. F. intumesces, gives 
off odor of sulphur, and yields a 
globule of silver. 



Gives odor of sulphur, also fumes, 
and coating of antimony, and yields 
a dark metallic globule, which after 
long blowing is colored red from 
oxidized silver, and from which 
silver may be obtained by addition 
of soda and heating in reducing 
flame. 



Miargy- 
rite. 



Ag,S.Sb 1 St. 
Silver, 



Brittle, with uneven fracture. Contains less silver than some of 

the kindred ores. 
Occurs with the other ores of silver. 



Fuses on charcoal quietly to a gray 
bead, with emission of sulphur and 
antimony fumes. If this bead is 
treated for some time in O. F. a 
bright globule of silver is obtained. 



134 



Characters. 



Treatment with Acids,btc. 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 
ness. 



Sp. Gr. 



Crys- 
talli- 
zation. 



Magnetic 
before 

OR AFTER 

Heating. 



Vsbs. 



As above under native Blackish Metal- Shin- 
silver. In open tube lead-gray. lie. ing 
gives off sulphurous gray- 
fumes, black. 



i-5 



2-2.5 



7-3 



See under heading Silver, 
etc. 



Soluble in dilute nitric Iron-black, 
acid, leaving residue 
of sulphur and oxide 
of antimony, copper 
plate becoming plated 
with silver as above 
under native silver. , . . 



Heated in closed tube fuses with de 
crepitation and gives slight subli- 
mate of sulphide of antimony after 
long heating. 



Decomposed by nitric 
acid, with separation 
of sulphur and anti- 
mony trioxide. De- 
crepitates in closed 
tube and yields anti- 
mony sublimate. In 
open tube sulphurous 
and antimonial fumes. 



Metal- 
lic. 



Iron- 
black. 



2.5 



6.3 



IV. 



See under heading Silver, 
etc. 



Ton-black 
to steel- 


Metallic 
— ada- 


Red- 
dish 


gray. In 

splinters 

blood-red. 


man- 
tine, 
nearly 
opaque, 





Easily 2-2.5 5.2 



See under heading Silver, 
etc. 



135 



Namk. 



COMP. AND 

pbkcbntagk 
of Important 
Constituent. 



Spkcipic 



General Characters and Associations. 



SILVEB AKD ITS COMPOUNDS.— Continued, 

AgiSbSi. Brittle with uneven or conchoidal fracture. 

Occurs with the other ores of silver, and principally with calcite, 
Silver, native arsenic, galena, etc. 

59-9* 



Dark-red 
Silver 
Ore 

(Pyrar- 
gyrite). 



Light- 
red Sil- 
ver Ore 
(Prous- 
tite). 



AgtAsSi. 

Silver, 

654* 



Like above, except that Sb is replaced by arsenic. 
Found with the other ores of silver, especially pyrargyrite, cerar- 
gyrite, native silver, and gold. 



Before Blowpipe, 



On charcoal fuses with spirting to a 
globule, and gives a white subli- 
mate of antimony trioxide. 



On charcoal gives garlic odor of ar- 
senic and sulphur. 



Polyba- 
site. 



Stro- 
meyer- 
ite 

(Silver- 
copper 
Glance). 



AgiSbSi. Uneven fracture. Copper is often present. Arsenic often re- 
places the antimony. Otherwise the formula remains the same 

Silver, (Mollie Gibson mine, etc., Colorado). A somewhat related ore 

75.6*. is freieslebenite* (PbAg t )»Sb 4 S,,, containing from 30* to 50* of 
lead and from a trace to 27* of silver. 

AgiS + Steel-gray argentiferous copper sulphide. Fracture subcon- 

CusS. choidal. 

Usually found associated with chalcopyrite and galena. 
Silver, 

53.1* 



Fuses with spirting to a globule. 
Gives off sulphur, sometimes ar- 
senic, and coats the coal white. 
Arsenical variety gives off charac- 
teristic garlic odor of arsenic. 

Fuses and gives in open tube an odor 
of sulphur. Silver globule yielded 
only by cupellation with lead. 



136 



Characters. 



Treatment with Acids,stc. 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 



Crys- 
Sf. Gr. talli- 

Z ATI ON. 



Magnetic 

BEFORE 
OR AFTER 

Heating. 



Uses. 



Like stephanite. 



Dark red ta Metallic 
black or — ada- 
grayish man- 
black, tine. 



Red. 



2.5 



5.8 



III. 



See under heading Silver, 
etc. 



Decomposed by nitric Cochineal- 
acid with separation red or 
of sulphur. scarlet. 



Decomposed by nitric Iron-black, 
acid, etc. In thin 

splinters 
cherry-red. 



Ada- 
man- 
tine. 


Ver- 
mil- 
lion, 
rarely 
aurora- 
red to 




orange- 
yellow. 


Metal- 
lic. 


Black. 



Easily 



*5 



5.5 



III. 



6.1 



IV. 



See under heading Silver. 
etc. 



See under heading Silver, 
etc. 



Nitric solution gives Dark steel- Metal- 
with HC1 a heavy gray. lie. 

precipitate. 



Same Easily 2.5-3 °- 2 5 
as 

color, 
but 
more 
shin- 
ing. 



IV. 



See under heading Silver, 
etc. 



137 



Namb. 



COMP. AND 

Percentage 
op Important 
Constituent. 



Specific 



General Characters and Associations. 



SILVER AND ITS COMPOUNDS.— Continued. 



Horn 
Silver or 
Silver 
Chlo- 
ride 
(Cerar- 
gyrite). 
Kindred 
and 
asso- 
ciated 
ores are: 



Embolite, 
which 
passes 
into 



AgCl. 

Silver, 

75-3*. 



Ag(ClBr). 

Silver, about 
64*. Very 
variable. 
Ratio of 
chlorine to 
bromine 
varying in- 
definitely. 



The common ore of Mexico and South America. Not common, 
except in southern part, in the United States. A very valuable 
ore, as it is easy of treatment (free-milling). It is an alteration 
product of the foregoing ores and owes its origin in many cases 
probably to the percolation of sea or salt water throughout the 
upper portions of the veins or other classes of deposits, as in 
depth the ores invariably change into their original condition of 
sulphides. Highly sectile when very pure, cutting like hard 
wax or a piece of horn; hence its name. Fracture somewhat 
conchoidal. No cleavage. Occurs massive and waxlike, or as 
incrustations. 

Found associated with the other ores of silver, but usually for the 
reasons given above, in the upper portions of the veins contain- 
ing silver ores. Often associated with oxide of iron and other 
alteration products. Found frequently with copper ores, calcite, 
barite, etc. 

A rare variety is huantajayite (2oNaCl -f- AgCl), which is found 
near Iquique, Chile, only, however, to a depth of 20 metres. 



The yellow and deep- 
quantities of bromine. 



Fracture uneven, no cleavage, sectile. 

green varieties contain the largest 

Abundant in Chile. 
Associated with the other silver ores, of which it is an alteration 

product. Also frequently associated with cerussite. 



Before Blowpipe. 



Fuses in flame of candle, emitting 
acrid fumes (CI). Malleable and 
sectile. On charcoal yields a glob- 
ule of metallic silver. In salt of 
phosphorus bead, to which oxide 
of copper has been added, and 
heated in O. F., an intense azure- 
blue color is imparted to the flame. 



Pungent bromine vapors are emitted 
when it is heated on charcoal, and 
a button of metallic silver remains. 



138 



^ 



Charactrrs. 
Trsatmsntwith Acids, etc. 



Soluble in ammonia, 
but not in nitric acid. 
In closed tube with 
bisulphate of potassa 
gives off acid vapors. 
Fuses to a pale hya- 
cinth-red globule. Be- 
comes yellow when 
cold. A plate of iron 
rubbed with the min- 
eral becomes silvered. 



Color. 


Lustre, 


Streak 


Fusi- 
bility. 


Hard- 
ness. 


Pearl-gray, 
whitish, and 
colorless; 


Resin- 
ous- 
ada- 


Shin- 
ing, 
trans- 


Very 

easily 


1-1.5 


upon expo- 
sure to light 
turns into 


man- 
tine. 


parent 
to sub- 
trans- 
lucent. 







Sr. Gr. 



5-5 



Magnetic 
brpork 

,*~.,w OR AFTRR 

ZATION. U. AT1NG . 



Crys- 

TALL1- 



TJsbs. 



See under heading Silver, 
etc. 



violet and 
other tints 
of brown. 
Passes into 
green and 
blue. 
Rarely 
violet-blue. 



In closed tube gives off 
bromine vapors and 
fuses to an intense 
garnet - red globule, 
which is yellow when 
cold. Soluble in am- 
monia, but not as solu- 
ble as the above. 



Gray-green, 


Resin- 


Shin- 


asparagus- 


ous to 


ing. 


green to 


some- 




yellow and 


what 




green-yel- 


ada- 




low; be- 


man- 




comes 


tine. 




darker on 






exposure. 







Easily 1-1.5 5-4 



See under heading Silver, 
etc. 



139 



Namb. 



Com p. and 
Pkrckntack 
op Important 
Constituent. 



Specific 



Genskal Characters and Associations. 



Before Blowpipe. 



SILVER AND ITS COMPOTJITCDS.— Continued. 

AgBr. No cleavage and fracture uneven, sectile. 



Bromy- 
rite. 



Abundant in Chile. 



Same as above. 



Silver, 

57-4* 



Iodyrite. Agl. Perfect cleavage. Sectile, plates flexible. Chile, New Mexico, B. B. gives fumes of iodine and me- 

Arizona, Spain, etc. tallic silver. 

Silver, 46*. Same as above. 
Iodine, 54*. 



Argentiferous Galena. (See Lead ores.) This very frequently carries silver, and is a very common ore of the latter. 

Argentiferous Cerussite. (See Lead ores.) This very frequently carries silver, and is a vtry common ore of the latter. Results 

Argentiferous Zinc Blende. (See Zinc ores.) This less frequently carries silver. Generally associated with galena, iron and 

Argentiferous Pyrites. (See Iron and Copper ores.) The various kinds of pyrites very frequently carry small percentages of silver. 

140 



Characters. 



Treatment with Acid«,«tc. 



In closed tube and with 
metallic zinc much the 
same reaction as cer- 
argyrite. Fused with 
potassium bisulphate 
gives off yellowish- 
brown vapors (Br). 
With difficulty soluble 
In ammonia. 



In closed tube fuses and 
assumes deep orange 
color, but is yellow on 
cooling. Fused with 
potassium bisulphate 
in a matrass yields 
violet vapors, and the 
globule becomes very 
dark or almost black. 



Color. 


Lustre. 


Stria k 


Fusi- 
bility. 


Hard- 
ness. 


When pure 


Resin- 


Shin- 


Easily 


*-3 


bright yel- 


ous to 


ing or 






low to am- 


ada- 


like 






ber-yellow; 


man- 


color. 






often grass- 


tine. 








green or 










olive-green. 










Externally 










little altered 










on ex- 










posure. 










Citron and 


Resin- 


Yellow, 


Easily 


Soft. 


sulphur- 


ous to 


trans- 






yellow to 


ada- 


lucent. 






yellowish 


man- 








green; 


tine. 








sometimes 










brownish. 











Sr. Gk. 



5-5-6 



Magnetic 

BEFORE 
. 1TmM OR AFTER 
lATION. Hbatwc# 



Crys- 

TALLI- 



USES. 



See under heading Silver, 
etc. 



5.7 



III. 



See under heading Silver, 
etc. 



usually from superficial decomposition of above, 
copper pyrites, etc., in silver mines. 



141 



Name. 



CoMP. ANfi 

Phkcbntagb 
or Important 
Constituent. 



Specific 



General Characters and Associations. 



Before Blowpipe. 



SILVER AND ITS COMPOUNDS.— Continued. 

Tetrahedrite (Gray Copper). (See Copper ores.) This frequently carries a large percentage of silver, but not often found in 

SULPHUR AND SULPHIDES, 

The following is usually sufficient to detect the presence of sulphur: Mix the substance suspected to contain sulphur with 
silver (coin or plate), and a drop of water is added. A yellowish stain on the silver indicates a trace of sulphur; larger 
sulphur. Mixed with soda as above and heated in O. F. on platinum wire, the sulphides color the coin brown to black, but 
and colors the coin. Sulphides, or substances containing sulphides in considerable quantities, yield sulphur dioxide when heated 
inserted in end of tube. Usually soluble in nitro-hydrochloric or concentrated nitric acid. Some are extremely difficult to dissolve 
upon it, but these can usually be recognized by their volatility, etc. (mercury, arsenic, etc.). The higher sulphides give off sulphur 

of burning sulphur. Uses. — 2'he chief use of sulphur is, of course, in the manufacture of sulphuric acid, this acid being produced in 

lucifer -matches, for bleaching, and for medicinal purposes. 



Sulphur. S. Taste is scarcely perceptible, odor when rubbed faintly sulphur- 

ous. Yellow when pure, but usually gray or brown because of 
admixture with earthy substances, clay, bitumen, etc. Fracture 
conchoidal to uneven. Associated with gypsum, calcite, celes- 
tite, and abundant in regions of present and ancient volcanic 
activity. Andes, Sicily, Mexico, Yellowstone Park, and almost 
world-wide distribution. 
Found often near sulphur springs, in many coal deposits, and at 
other places where pyrites is undergoing decomposition. 



Melts at io8° C. (some varieties at 
114 C.) and at 270 burns with 
blue flame, emitting the suffocating 
odor of sulphurous acid gas, which 
it forms by combining with the oxy- 
gen of the air. 



TELLURIUM AND ITS COMPOUNDS. 

Rarely occurs native, when it is a white and brittle metal, which is easily fusible, volatilizing almost entirely and tinging 
decomposing horse-radish. Usually combined with the other metals as tellurides of gold, silver, lead, and bismuth, which see. In 

in nitric acid. Occurs usually accompanying quartz, pyrite, gold, fluor-spar, etc. Uses. — Of no use in the arts. 

142 



Characters. 

Treatment with Acids,etc 



«. « Crys- Magnetic 

Cou>r. Lustre. Streak J|*£ »££' Sr. G*. talu- ™ b 

ZATION. Hbatwg# 



'JSBS. 



large quantities. When argentiferous its color is usually steel-gray, or lighter than the ordinary varieties. 

soda (3 soda. 1 substance) and heat on platinum wire or charcoal in R. F. The fused mass is then crushed on a clean piece of 
quantities give a brown or a black stain. Sulphides such as pyrites, galena, etc., heated on charcoal give the odor of burning 
sulphates, gypsum, baryta, etc., so treated in O, F.,do not color the coin; in R. F., however, the sulphate is changed to sulphide 
»n open tube. The sulphur dioxide may be recognized by its odor, and by reddening and sometimes bleaching blue litmus paper 
completely, owing to the deposition of sulphur, which fuses around the unaltered substance and prevents any action of the acid 
when heated in closed tube. Free sulphur (q. v.) fuses and sublimes, and on charcoal burns with a blue flame, and affords odor 
commercial quantities only from native sulphur and pyrites. It is also largely used t however, in the manufacture of gunpowder and 



Insoluble in water. 
Natural and arti- 
ficially formed crys- 
tals are soluble in di- 
sulphide of carbon, 
but the amorphous 
form is not. Crystal- 
line forms also soluble 
in sulphide of chlo- 
rine, benzine, turpen- 
tine, etc. Not acted 
on by acids. 



Sulphur-yel- 
low, gray, 
brown, or 
reddish to 
greenish. 



Resin- 
ous. 



Like 
color. 



Easily 1.5-2.5 2.07 



IV. 



See under heading Sulphur, 
etc. 



the flame green. White coating on charcoal. It fumes strongly, and in presence of selenium gives the peculiar odor of 
ooen tube a white or grayish sublimate (tellurium dioxide) is obtained, which may be fused to clear, colorless drops. Soluble 



143 



Nam*. 



0>MP. AND 

Percentage 
op Important 
Constituent. 



Spbcipic 



GSNEEAL ChAKACTSRS AMD ASSOCIATIONS, 



Before Blowpipe, 



TIN AND ITS COMPOUNDS. 

Fused with soda and borax on charcoal in R. F., the compounds of tin yield a globule of the metal. At the same time a 
must be kept covered with the blue R. F. The coating moistened with cobalt solution and heated in the O. F. assumes a bluish- 

with metallic zinc, metallic tin is thrown down in the form of scales, or as a gray spongy mass. Uses. — Tin, as a metal, has a 

sheet iron (tin plate), ete. It is largely used as an alloy, e.g. t with copper, forming bell-metal, in the manufacture of solders, etc. It is 
is employed for polishing hard stone and sharpening fine cutting instruments and in enamels. The chlorides are used in dyeing and 
bronze-powder. 



Tin 
Stone 
(Cassi- 
terite). 
(Stream 
Tin.) 



SnO s . 
Tin, 78.6* 



Tin 


CuiS.FeS, 


Pyrites 


SnS«. 


(Stan- 




nite). 


Tin, 27. 5* 




Copper, 




39-5* 



Practically the only ore. Its high specific gravity is very notice- 
able; likewise its hardness. (Compare garnet and rutile.) Frac- 
ture uneven or subconchoidal. When found in place it is usually 
associated with quartz, copper, and iron pyrites, wolframite, 
mica, tourmaline, apatite, fluorite, sphalerite, molybdenite, ar- 
senopyrite, etc. When in place it is usually found in veins in 
granite, quartzose gneiss, quartzite, metamorphic slate, mica 
schist, and porphyry. It is, however, quite largely obtained 
from placer deposits,' when it is frequently associated with plati- 
num, iridosmine, gold, corundum, etc. 

Sulphide of tin. " Bell-metal ore." Rare. Easily fusible. Mas- 
sive, granular, and disseminated. Cubic cleavage, uneven frac- 
ture, and brittle. Often yellowish from presence of copper 
pyrites. Zinc is often present. 

Commonly found massive and associated with tin-stone (cas- 
siterite), wolframite, also in quartz with native bismuth, scheel- 
ite, pyrite, galena, sphalerite, etc. 



B. B. alone unaltered. With soda on 
coal reduced to metallic tin, and 
gives a white coating, Requires 
long blowing. Hastened by addi- 
tion of potassium cyanide. The 
globule is malleable, and reacts for 
tin. Sometimes reacts for iron and 
manganese. The fine powder gives 
tin reaction with cobalt nitrate. 



On charcoal after long blowing fuses 
to a brittle metallic globule, which 
in O. F. gives off sulphur and coats 
the coal white with oxide of tin. 
In open glass tube gives off sulphur 
(forming fumes of sulphurous acid) 
and also forming close to assay 
sublimate of oxide of tin, which 
cannot be volatilized by heat. 



144 



Characters. 



Treatment with Acids, etc. 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 
ness. 



Sp. Gr. 



Magnetic 
before 

.._.-„ OR AFTER 

ZAT1 ° N - Heating. 



Crys- 
talli- 



ne*. 



coating is formed on the coal, which is slightly yellow when hot, but white when cold. To obtain a coating, however, the assay 
green color. Sulphides should always be roasted. When a solution of salts of tin, acidulated with HC1, is brought in contact 
wide application in the industries. It is employed for making castings, and very extensively for coating iron and copper vessels, especially 
also used in the manufacture of tin-foil, and when amalgamated with mercury for silvering mirrors. The dioxide (prepared artificially) 
calico-printing. The bisulphide, on account of its golden lustre, is used in ornamental painting, etc., and known under the name of 



Insoluble in acids or 
only slightly acted 
upon. 



Soluble in nitric acid 
to a blue solution, with 
separation of sulphur 
and binoxide of tin. 



Brown, 


Ada- 


White- 


Infus. 


black, and 


man- 


brown. 
Trans- 
parent 




brown- 
black, 
sometimes 


tine to 

dull. 

Crys- 




red, gray, 


tals 


to 




white, or 


usually 


opaque 




yellow. 


splen- 
dent. 






Steel-gray 


Metal- 


Black- 


Easily 


(when pure) 


lic. 


ish. 




to brown- 








black. 








Sometimes 








a bluish 








tarnish. 









6-7 6.8-7.1 



II. 



See under heading Tin, etc. 



4.4 



Us- 
ually 
mas- 
sive. 



See under heading Tin, etc. 



145 



Name. 



COMP. AND 

percentage 
of Important 
Constituent. 



General Characters and Associations. 



Specific 



Before Blowpipe. 



Topaz. A] ls Si«O S6 F 10 Cleavage both perfect and imperfect. Fracture subconchoidal to uneven. B. B. Infusible. Fused in closed tube with 
Brittle. The colorless varieties resemble diamonds, but are easily d is tin- salt of phosphorus previously fused, etches 
guished from them in that they are of inferior hardness, that they lack the glass and gives off silicon fluoride. 
41 fire "and become electric when heated. The color of the deep wine-red Some varieties become yellow or more often 
crystals is apt to fade out on exposure to daylight, and the yellow color of pink when heated. Moistened with cobalt 
some of the crystals from Brazil is changed to rose-red by being heated. nitrate and ignited assumes a fine blue 
Oriental topaz is yellow corundum and Scotch topaz is yellow smoky quartz, color. v 
from each of which true topaz is easily distinguished. Occurs either crystal- 
lized, in association with granitic, gneissoid, 01 talcose rocks, or in the lorm ^ ____ _^____— __^ 

of rolled pebbles in gravel. The associated minerals are tourmaline, mica, beryl, and sometimes apatite, fluorite, and cas-j 
siterite. Sometimes found in cavities in rhyolite and similar volcanic rocks. Siberia furnishes the best stones, but many 
are obtained from Brazil. Also found in New South Wales, Tasmania, Mexico, and sometimes in the United States. 

TUNGSTEN AND ITS COMPOUNDS. 

Before blowpipe compounds of tungsten impart to salt of phosphorus bead at first a dirty-green, then a blue color when 

phosphoric acid its compounds give a beautiful blue syrup. Often associated with tin ores, etc. The ores are rare. U*g» — The 

hardening steel), the tungsten imparting to the steel a high degree of hardness. Tungstate of soda has been employed as a mordant in 
like alum, can, however \ be used for the same purpose. Also used for hardening plaster of Paris and in the manufacture of tungstic acid. 



Wolfram- (Fe,Mn,) Swedish heavy stone. Its true nature will be suspected from its great weight, 

ite. WO4. very dark-grayish or reddish-black color, submetallic or adamantine lustre, 

and red-brown streak. Tungstate of iron and manganese. Both massive 
Tungsten and crystalline. Breaks readily into angular fragments. Variety, Tungstite 

trioxide (WO|), which reacts for tungsten only, and which occurs in soft, bright 

= 76.47*. yellow or yellowish-green earthy masses. Due to decomposition of wolfram- 
Manganese ite, which, commercially speaking, 'is the only ore. Hubnerite is a nearly 
and Iron pure manganese wolframite (MnWOf). 

very varia- Usually occurs in quartz veins, sometimes quite massive, sometimes dissemi- 
ble. nated throughout the vein material, and frequently as nests or bunches 

irregularly distributed through the gangue. Very frequently associated with 
cassiterite, also with bismuth, scheelite, pyrite, galena, sphalerite, etc., some- 
times with gold. 



Fuses quite easily to gray and often crystal- 
line globule which is magnetic. With 
borax manganese reaction. With soda on 
platinum-foil gives the bluish-green man- 
ganese reaction. With salt of phospho- 
rous gives a clear reddish-yellow glass 
when hot, which is paler on cooling; in 
R. F. becomes dark red ; on charcoal with 
tin, if not too saturated, bead becomes 
green on cooling, and with continued 
treatment in R. F. changes to reddish 
yellow. Often feebly magnetic. 



146 



Characters. 

Treatment with Acids, etc 

Not affected by acids or 
only partially affected by 
sulphuric acid. 



Color. 



Colorless, pale 
vellow, white, 
bluish, green- 
ish and red- 
dish. 



Lustre. Streak 



Vitreous. 
Transpa- 
rent to 
subtrans- 
lucent. 



White. 



Fusi- 
bility. 



Infusi- 
ble or 
fusible 
above 
5- 



Hard- 
ness. 



Crys- Magnetic 

Sp. Gr. talli- "!£!» 

t.tioh OR AFTER 

zatioh. Heating 



3.65 



IV. 



Uses. 



The purer varieties are used as 
gems in jewelry. Owing to its 
perfect cleavage, it is a poor sub- 
stitute for emery. 



cold. If iron is present the bead appears blood-red. Best with tin on charcoal. Characteristic reaction is when boiled with 
chief use of tungsten ore is in the preparation of ferro-tungsten and tungsten metal for making tungsten steel (ordinarily called self- 
dyeing, and for the impregnation of vegetable tissues, linen, cotton, and other light fabrics, to render them non-inflammable. Cheaper salts, 



Reduced to fine powder and 
boiled with aqua regia, 
assumes gradually a yel- 
low color. Boiled with 
phosphoric acid gives a 
beautiful blue syrup 
(tungsten). The blue 
syrup is changed to violet 

by addition of nitric acid. 

It is sufficiently decomposed by concen 
trated sulphuric or even hydrochloric acid 
to give a colorless solution which, when 
treated with metallic zinc, becomes intensely 
blue, but soon bleaches on dilution, 



Black, dark 


Subme- 


Black 


grayish to 
brownish 


tallic to 


to dark 


resinous, 


reddish 


black. Also 


adaman- 


brown, 


brownish 


tine. 


yellow- 
brown 


red and hair- 


Some- 


brown. 


times 


and 




splen- 


green- 




dent. 


ish 



gray. 



a-5-3 



5-5 



7.3 



Both. See under heading Tungsten, etc 



147 



Name. 



Com p. and 
Percentage 
or Important 
Constituent. 



Specific 



General Characters and Associations. 



TUNGSTEN AND ITS COMPOUNDS.— Continued. 
CaWO*. 



Scheel 
ite. 



Tungsten, 
63.8*. 



Tur- 
quois. 



2Al s O«, 

P10., 

5H.O. 
Variable. 



Cleavage very distinct. Brittle, with uneven fracture. Reniform, 
massive, granular. Molybdenum is usually present, replacing 
part of the tungsten. Found usually in crystalline rocks asso- 
ciated with tinstone, apatite, fluorite, topaz, wolframite, molyb- 
denite, and in quartz along with gold, etc. 



Before Blowpipe. 



A hydrous phosphate of aluminum colored by presence of some 
compound of copper. Rather brittle, no cleavage. In thin 
seams and disseminated grains. Usually in trachytic rocks, or 
in the neighborhood of them, as very thin seams or small masses 
in the cracks or joint planes, etc. 

In Persia it is found not only in the brecciated trachyte, but in 
the surrounding clay slate. 



In forceps fuses with some difficulty 
to a semi-transparent glass. With 
borax the glass is transparent, but 
on cooling it becomes opaque and 
crystalline. With salt of phosphorus 
the glass is colorless in the outer 
flame, but is green in the inner 
flame when hot, and a fine blue when 
cold. If iron is present specimen 
must be treated with tin before this 
effect is obtained. 

In forceps becomes brown and glassy, 
but does not fuse. Colors flame 
green. Moistened with HC1 the 
color is at first blue. With the 
fluxes gives yellowish-green beads 
when hot, which are pure green on 
cooling. 



148 



Characters. 



Treatment with Acids, etc 



In hydrochloric or nitric 
acid is decomposed, 
leaving a yellow pow- 
der which is soluble in 
ammonia. 



Soluble in hydrochloric 
acid. In closed tube 
decrepitates, yields 
water, and turns 
brown or black. 



Color. Lustre. 


Streak 


Yellow, yel- 


Vitre- 


White 


lowish 


ous to 




white, pale 


ada- 




yellow, 
brownish, 


man- 
tine. 




greenish, 
reddish, 
and rarely 


Trans- 
parent 
to 




orange- 
yellow. 


trans- 
lucent. 




Sky-blue, 
bluish 


Waxy, 
feeble. 


White 
or 


green to 
apple- green 
and green- 




green- 
ish. 
Sub- 


ish gray. 




trans- 
lucent 
to 



Fusi- 
bility. 



Hard- 
ness. 



4-5-5 



Sr. Gr, 



Crys- 
talli- 
zation, 



Magnetic 

before 

or after 

Heating. 



II. 



Uses. 



See under heading 
sten, etc. 



Tung- 



Infus. 



2.6 



The principal use is in jew- 
elry. Fossil bones and teeth 
colored by phosphate of iroi . 
and termed odontolith, or 
bone turquois, are fre- 
quently cut and polished 
for the same purpose. 



opaque 



149 



Nams. 



Wollas- 
tonite 
(Tabular 
Spar). 
(A vein- 
stone.) 



Comp. AND 
Percentage 
of Important 
Constituent. 

CaOsSi. 



* Specific 



General Characters and Associations. 



A somewhat rare veinstone (in the same sense that baryta, calcite, 
etc., are veinstones). Brittle, with uneven fracture, but perfect 
cleavage. Usually with long fibres or columnar structure. In 
granitic regions, in granular limestones, and along with some 
basaltic lavas. 

Often found associated with lime garnet, pyroxene, etc. 



Before Blowpipe. 



Fuses quietly, but with difficulty, to 
a colorless translucent glass. In 
closed tube no change. With much 
soda swells up and becomes in- 
fusible. 



ZINC AND ITS COMPOUNDS. 

Compounds of zinc with borax give a clear glass, which is milk-white on flaming, or with more assay becomes enamel-white 
is yellow when hot, but white when cold. With soda on charcoal the ores, even when containing little zinc, afford the peculiar 
yellowish- or dirty-green color is obtained (either alone or with soda), while tin gives a bluish-green color when similarly 
what is known as galvanized iron. Its alloys with copper , lead, tin, and other metals are of great importance; e.g., with coppei making 



Zinc- ZnS. The most abundant ore. Generally can be recognized by its 

blende appearance. It is massive, cleavable, coarse to fine granular, 

(Spha- Zinc, 67*. and compact; also foliated and fibrous, radiated and botryoidal. 

lerite; Brittle. Fracture conchoidal. Sometimes contains iron, man- 

Black- ganese, etc. Is frequently argentiferous or auriferous. Corn- 

jack), mon in silver mines. 

Occurs in rocks of all ages, in veins, in contact deposits, or in 
irregular pockets in limestone, etc., and is frequently associated 
with the ores of lead, as well as those of copper, iron, silver, 
gold, and tin; also frequently associated with quartz, barite, 
fluorite, calcite, etc. Widely distributed. 

100 



With soda on charcoal gives in R. F. 
a strong green zinc flame and a 
coating of oxide of zinc, with fumes 
of sulphur. Alone on charcoal 
gives fumes of zinc when strongly 
heated. Sometimes phosphorescent 
when rubbed or struck with a stick. 



Characters. 

Treatment with Acids,btc. 

Decomposed by HC1, 
frequently efferves- 
cing slightly from 
presence of small 
quantities of cal- 
cite, and gelatinizing. 
After separation of 
the silica, carbonate 
of ammonia causes a 
copious separation of 
carbonate of lime. 



Color. 



Lustrr. Streak 



Fusi- 
bility. 



Hard- 
ness. 



White to 


Vitre- 


whitish 


ous to 


gray. In 


pearly 


some speci- 


on 


mens yel- 


cleav- 


lowish, 


age 


reddish, 


sur- 


and 


faces. 


brownish. 





White 4-5 4-5 



Sp. Gr. 



2.9 



Crys- 
talli- 
zation. 



Magnetic 
bbfork 

OR AFTER 

Heating. 



TJstS. 



V. 



on cooling. In the R. F. on charcoal burns with a greenish-blue flame. Fumes are given off depositing much oxide, which coating 
bluish flame of burning zinc, and the oxide is deposited on the coal. When this coating is moistened with cobalt nitrate, a fine 

treated. Uses. — Zinc is extensively employed in sheets for roofing and other purposes \ and for coating \ as in the manufacture of 

brass, etc. The white oxide of zinc is much used for white paint in place of white lead, and also in making a glass for optical purposes. 



Dissolves in nitric acid, 
emitting sulphuretted 
hydrogen. Soluble 
also in HC1. 



Brown, yel- 


Resin- 


low to 


ous or 


black, 


waxy 


sometimes 


to ada- 


green, red, 


man- 


and white; 


tine. 


nearly col- 




orless when 




pare. 





Brown- 
ish to 
light 
yellow 
and 
white. 
Trans- 
parent 
to 

trans- 
lucent. 



Infus. 
or 

with 
diffi- 
culty. 



3.5-4 



See under heading Zinc, etc. 



151 



Name. 



COMP. AND 

Percentage 
of Important 
Constituent. 



Specific 



General Characters and Associations. 



ZING AND ITS COMPOUNDS.— Continued. 



Zinc 
Carbon- 
ate 

(Smith- 
sonite; 
"Dry- 
bone "). 



ZnCO,. 
Fe, Mn. 
Ca, and 
Mg often 
present. 

Zinc, $2%. 



Before Blowpipe. 



Zinc 


Zn,Si0 4 


Silicate 


+ H.O. 


(Cala- 




mine; 


Zinc, 54.2*. 


Electric 




Cala- 




mine). 





Crystals over drusy surface usually terminate in sharp three-sided 
pyramids. Faces of crystals generally rough and curved. 
Reniform, botryoidal, or stalactitic and incrusting. Roughly 
friable and sometimes earthy. Usually rough and granular. 
Markedly harsh to feel. Brittle. Cleavage perfect, but frac- 
ture uneven. Found in veins, but more usually in irregular 
deposits in limestone strata. Usually produced by action upon 
zinc sulphide of carbonated waters, and is therefore nearly 
always an alteration product of the originally deposited ore. 
Associated with blende, calamine, galena, and with limonite 
and copper ores. An earthy variety is zinc-bloom, (hydrozincite). 



Infusible alone, but CO* and zinc 
oxide are finally vaporized with 
toda on charcoal, producing coating 
which can be treated as above. 



Stalactitic, mammillary, botryoidal, fibrous, but also massive and 
granular, sometimes cellular. In physical characters somewhat 
resembles the preceding ore. An anhydrous variety of this ore 
is willemite^ which is found with the two following ores in New 
Jersey (Mine Hill and Sterling Hill). 

Like the former, it is usually found in veins, or in beds, or in 
irregular pockets in stratified calcareous rocks, in association 
with zinc-blende, zinc carbonate, iron and lead ores, etc. 



The smallest fragment heated at- 
tracts light substances. Pyro-elec- 
tric. Almost infusible. Moistened 
with cobalt solution gives a blue 
color when heated. 



152 



Characters, 



TREATMENT WITH Ad06,BTC 



Gives little or no water 
in closed tube. Dis- 
solves in HC1, with 
evolution of carbonic 
acid, causing effer- 
vescence. 



Colo*. 


Lust**. 


Streak 


Fusi- 
bility. 


Hard- 

HESS. 


Impure 
white to 
grayish, 
sometimes 


Vitre- 
ous, 
pearly. 
Sub- 


Un- 
col- 
ored 
or 


Infafl. 


5 


green or 
brownish 
and other 


trans- 
parent 
to 


white. 






tinges. 


trans- 
lucent. 









Sr. Gr. 



4-4 



Crys- 
talli- 
zation. 



III. 



Magnetic 



or after 
Heating. 



Uses. 



See under heading Zinc, etc. 



Gives much water in Whitish or Vitre- 
closed tube. With 
HC1 forms a perfect 
jelly even when pre- 
viously ignited. De- 
composed by acetic 
acid and soluble in 
strong solution of 
caustic potash. 



Un- 



white, 


ous or 


col- 


sometimes 


sub- 


ored 


with 
bluish- 


pearly 
to ada- 


or 

white. 


green or 
brownish 


man- 
tine. 




tinges. 
Also 






yellowish 
to brown. 







4.5-5 



3.5 



IV. 



See under heading Zinc, etc. 



163 



Name. 



Com p. and 
Percentage 
of Important 
Constituent. 



Specific 



Gknekal Characters and Association!. 



Before Blowpipe. 



ZINC AND ITS COlffPOUNDS.-Continued. 



Red Ox- 

ide of 

Zinc 

(Zincite; 

Ruby 

Zinc). 

Frank- 

linite. 



Zircon. 



ZnO«MnO Distinguished by its eminent cleavage, infusibility, and by Its 
is fre- mineral associations. It is brittle and has subconchoidal fre- 
quently ture. On exposure to the air it decomposes superficially and 
present. becomes coated with white films of zinc carbonate. 

Occurs with franklinite and willemite in New Jersey, and some- 
Zinc, 80.3*. times in lamellar masses in pink calcite. 

(Fe,Zn,Mn) See Iron Ores, among which it is enumerated, although it is a very important zinc ore and is extensively 

0.(Fe,Mn)i Hill and Mine Hill, N. J. Usually contains about 103c zinc, the residuum, known as ." clinker, 

~ Vari- manufacturers of spiegeleisen. 



Infusible alone, but yields a yellow 
transparent glass with borax. If 
manganese be present, the bead is 
amethystine. Zinc coating on coal 
when treated with soda in R. F. 



O, 

able, 

Zinc, 



I2*(?). 



ZrSiO«. 



A somewhat rare mineral. Generally in crystals (square four- 
sided prisms terminated by four-sided pyramids); also in grains, 
etc. Brittle. Conchoidal fracture. 

Confined to crystalline rocks, usually occurring in granite, syenite, 
some of the gneisses, granular limestone, chloritic and other 
schists, and in some igneous rocks. Sometimes it is found in 
iron-ore beds; is also found in alluvial deposits associated with 
precious stones and gold. 



Becomes colorless upon heating. In 
powder is decomposed when fused 
with soda on platinum wire. 



I A 



154 



Characters. 



Treatment with Acids, etc 



Color. 



Lustre. Streak 



Fusi- 
bility. 



Hard- 

NESS. 



Sf. Gr. 



Crys- 
talli- 
zation. 



Magnetic 
before 

OR AFTER 

Heating. 



Heated in closed tube 
blackens, but resumes 
its original color on 
cooling. Soluble in 
acids without effer- 
vescence. 



Deep red to 
orange- 
yellow. 



Subada- 
man- 
tine. 



Orange 
yellow. 



Infus. 4-4.5 5-6 



III. 



See under heading Zinc, etc. 



mined in New Jersey for the extraction of this metal. Occurs with wHlemite and zincite at Sterling See under heading Zinc, etc. 
remaining after the extraction of the zinc, being treated as a manganese ore and sold to the 



Fused with soda, and 
the fusion dissolved 
in HC1, the dilute acid 
solution turns tur- 
meric paper orange- 
yellow (zirconia). Not 
acted upon by acids 
except in fine powder 
with concentrated sul- 
phuric acid 



Red, brown, 


Ada- 


Un- 


yellow, 


man- 


col- 


green, or 


tine. 


ored. 


gray; pale 






yellowish 






to 






colorless. 







Infus. 7.5 



45 



II. 



Used to a small extent 
jewelling watches. 



155 



II.-CLASSIFICATION OF MINERALS. 

(AFTER BRUSH.) 

MINERALS WITH METALLIC LUSTRE. 

A. Fusible from 1-5, or easily volatile: — Native antimony — stibnite — native arsenic — arsenopyrite — bismuth — bismuth glance 

tetradymite wit tic kite — smaltite — cobalt glance — linnaitt— native copper — copper pyrites— chalcocite—bornite—tetrahedrite — native 

gold— sylvanite—nagyagite— magnetite— hematite (specular iron)— iron pyrites— marcasite—pyrrhotite — galena— native mercury-ein- 
naoar — niccolite —pent land iu — millerite—ullmannite—gersdorffite— platinum— silver— argentite— stephanite— dyscrasite— miargyrite— 
palybasite—freieslebenite—stromeyerite—stannite— wolframite. 

B.— Infusible or fusible above 5, and non-volatile : — Chromite— graphite — iridosmine — magnetite — hematite (specular iron) — 
turgite—limonite—ilmenite—franklinite—pyrolusite—psilomclane—braunite—manganite—hawmannite—mo 

MINERALS WITHOUT METALLIC LUSTRE. 

A.— Easily volatile, or combustible B. &r.— VaUntiniti--kermesite—orpiment--realgar—cinnabar- : -cal0mel— sulphur. 

B.— Fusible 1-5, and non-volatile, or only partially volatile. (I) Those which yield a metal or magnetic mass with 
soda '. — Bismutite — crocoite — cobalt bloom— malachite— azurite—atacamite— cuprite— almandite— iron lime garnet— hematite— siderite 
— cerussite — rhodonite — wulfenite — annabergite —pyrargyrite —proustite — cerargyrite—embolite—bromyrite—iodyrite— wolframite— 

hubnerite. 

156 



(II) Those which do not yield a metal or magnetic mass with soda : — Cryolite— potash alum (kalinite) — apatite — asbestos 
{amianthus, actinolite) — barite — borax— gypsum— epidote—orthoclase—oligoclase—albite—fiuor-spar— halite— hornblende (amphibole)— 
rhodonite— nitre (common saltpetre, Chile saltpetre)— obsidian— pyroxene— scheelite—wollastonite. 

C. — Infusible, or fusible above 5 : — Bauxite — cervantite — apatite — asbestos (chrysotile or bostonite) — calcite (limestone) — dolo- 

mtte asboltte — chrysocolla — corundum— diamond— emerald— fire-clay — chrome garnet — turgice-^ limonite—bog iron ore — siderite — a n kerite 

kaolinite — chlorite — serpentine — talc — magnesite — wad— rhodochrosite— mica (muscovite) — mono zite— gent hite — zaratite — opal— hyper- 

sthene—ruby—rutile — sapphire— quarts— cassiterite—scheelite—turquois — sphalerite — smithsonite — zinc-bloom — calamine — willemite — 

tin cite — zircon. 

Hydrocarbons :— Anthracite— bituminous coal— lignite— asphalt. 



157 



Ill.-APPENDIX. 

TEST FOB ALL CABBONATES (Caloite, Dolomite, Malachite, Siderite, Ceruasite, etc*). 

Make a bead of salt of phosphorus % and heat in O. F. until all bubbles are out. Then take up a minute fragment of the 
mineral to be tested in the bead and heat in O. F. If the fragment gives off gas or effervesces in the bead, causing bubbling in 
the bead, it is a carbonate. The usual effervescence with hydrochloric and nitric acids is a further test. 

TEST FOB SILICA AND SILICATES. 

The substance to be tested is broken, and a fragment heated for three minutes in the O. F. in a bead of salt of phosphorus \ 
as for carbonates. Silica and most silicates give a skeleton of undissolved silica, which remains in the bead. Metallic oxides and 
other salts are dissolved, leaving no skeleton. Some silicates do not give this reaction, but quartz always gives it. 

TEST BY HEATING WITH COBALT NITBATE. 

The mineral is ignited strongly in the O. F. and then moistened with a drop of cobalt nitrate and again ignited. The 
fragment may be supported on charcoal or in the platinum forceps. 

Alumina gives a blue color (clay, etc., same). 

Magnesia gives a pink color. 

Zinc and Tin (see description). The coating on charcoal produced by burning zinc when moistened with cobalt nitrate 
gives a yellow or dirty-green color. The coating on charcoal produced by burning tin when so moistened gives a bluish-green 
color. 

Silica gives a faint bluish color. Generally partially fused. 

Note, — All minerals assuming a dark color on heating, or remaining dark on heating, cannot be used in this test. 

158 



TEST BY FLAME COLORS. 

A long colorless O. F. is blown. A fragment of the substance is then approached to the flame (being held in platinun 
forceps). When it touches the flame just back of the inner blue point, the color imparted to the flame beyond this is to be noted. 
Calcium gives a reddish-orange color (calcite, dolomite, etc.). 
Barium gives a yellowish-green color (barite, witherite, psilomelane, etc.). 
Strontium gives a scarlet color (celestite, strontianite, etc.). 
Sodium gives an intense orange-yellow color (feldspar, Chile nitre, etc.). 
Potassium gives a violet or lavender color (feldspar, etc. ; also common nitre). 
Lithium (rare) gives a deep-red color, with tinge of purple (lepidolite, etc.). 

A FEW SIMPLE TESTS. 

A. — Lead, If the specimen is very heavy, and on cutting shows a surface having a grayish metallic appearance, it may 
be galena or lead sulphide. If it is heavy, with no metallic shine, and of a yellowish color, it may be carbonate of lead. In 
either case put a few drops of nitric acid on the rock, then after a minute as much water, and finally place a small piece of 
iodide of potash on the wet spot. If the rock turns a bright yellow, lead is present, etc. 

B. — Copper, Specimens having a strong blue or green color, or with a gray metallic lustre, and hard to cut, should be 
tested for copper. Treat with nitric acid, as before; then add quite a little ammonia-water; if the sample turns a very deep blue, 
copper in some form is in the ore. (Do not confound with nickel.) 

C. — Silver, For silver, grind a small fragment to a fine powder; put one half in a small bottle with a little strong ammonia- 
water; shake, cork, and let stand for some hours; pour off the solution, and add an equal quantity of nitric acid. If the liquid 
becomes milky, or a curdy mass forms in it, there is chloride of silver in the ore. The other half is to be heated in a test-tube 
with nitric acid, the solution poured off, and a grain or two of common table salt added. If a curdy mass forms which does not 
dissolve in boiling water (but does dissolve in ammonia) and turns dark on exposure to light, silver is present. 

D. — Gold, Gold can be proven with certainty only by '* panning" or assaying. (W. L. Brown.) 

159 



PROCESS OP ASSAYING POE SILVER AND GOLD. 

(A) By the Scorification Method. 

In brief : Grind ore in mortar very fine, so that it will pass through an 8o-mesh sieve, and weigh one tenth of an assay ton of 
it. Next weigh about one assay ton of test lead and divide in halves; put one half in a scorifier and mix with it the ore; place the 
other half on top, and add a piece of borax glass the size of a pea; heat in a furnace in a muffle till everything in the scorifier is 
melted and no vapors of lead arise from it. Take out, pour in an iron mould, break slag from button with a hammer, place button 
in a cupel in the muffle, and heat until the lead has been driven off; weigh in milligrammes bead left in cupel, which bead equals 
gold and silver. Place this bead in a test-tube and heat with nitric acid to dissolve the silver; pour off acid and wash with dis- 
tilled water, take out the gold, dry and weigh; first weight less second, equals silver; each result multiplied by ten, equals the 
number of ounces troy per ton avoirdupois of the precious metal contained in the ore. Often advisable to unite a number of 
buttons when separating the gold from the silver. 

(B) By the Crucible Method. 

Used where the character of the ore is well known and flux prepared accordingly. Weigh one-half an assay ton of the 
pulverized ore, add requisite amount of flux (50 to 80 gms.), cover with borax glass, fuse in muffle from twenty to forty minutes, 
pour in mould, and proceed exactly as in the scorification method except as to multiplying the weights by two instead of by ten. 

ASSAYS OP SILVER ORES.-B. B. 

An amount equal to 100 mgm. of the ore is weighed out, and mixed with 500 mgm. test-lead, and one spoon (about 100 
mgm.) borax glass, the mixing being done in the brass scoop. Make a cartridge of soda-paper (this is filter-paper soaked in soda 
solution and then dried), place the mixture in the cartridge, and fold up tight. Then put the cartridge in the charcoal crucible 
and heat in a good reducing flame until all the paper is charred. Keep covered by the reducing flame until all paper is burned 
and the lead is in one button and the slag in another. Then oxidize in O. F. until the lead button is yellowish on cooling, and red 
when hot. (As long as the sulphur remains in the button it will be dark gray or black on cooling, not yellow.) When the button 
is yellow when cool, pour out on the anvil, make a cupel, and heat it to expel moisture; then place the button on the cupel and heat 
until it has been reduced to one-tenth inch in diameter. Allow the litharge formed to collect around the button; conduct this part 

160 



of the operation at a low temperature. Now make another cupel; prepare the surface by oxidizing a little test-lead and driving 
the oxide into the cupel; place the button broken from the former cupel on this newly-prepared one and complete the cupellation. 
In this last operation direct the flame (hot O. F.) at the cupel around the button rather than at the button itself, and do not allow 
the bottom of the cupel to become '* wet," i.e., keep all the litharge soaked up by the cupel. As the button nears the glance, 
white specks appear on its surface, then a play of prismatic colors, then for a moment it is dull, and suddenly it breaks out in a 
bright glow, which almost immediately fades. This last is the glance; when it fades the cupellation is complete; stop blowing. 
Weigh in mgms.; this gives percentage, i per cent, or each milligramme = 291.66 oz. per ton. 

In case of poor ores cupel several portions of 100 mgm. down to one-tenth inch as above, and then unite these buttons 
and cupel to a finish. The final button may be weighed, or if less than 1 mgm. it may be measured on the Plattner scale, and 
the weight thus ascertained. 

ASSAYS OF MEBCUBY ORES. 

Mix 500-1000 mgms. in fine powder with 5-10 gms. litharge and introduce into a tube, bent with an elbow. This glass tube 
is one-fifth inch in diameter and seven to eight inches long. Heat until the assay is fused and the glass becomes attacked. Mer- 
cury collects beyond the elbow in drops; condense the deposits there by careful heating; break the tube and weigh portion with 
mercury. Then clean out mercury and weigh again; difference is mercury; 0.05 per cent may be thus estimated. 

TO OBTAIN PERCENTAGE OF A GIVEN ELEMENT IN AN ORE. 

To get the percentage of any element in a given ore or compound is simply a matter of proportion — e.g., Magnetic Iron 
Ore (Fe,0«). First refer to tables of atomic weights, and we find the atomic weight of iron (Fe) to be 56, which multiplied by 3 
gives 168; while the atomic weight of oxygen (O) is 16, which multiplied by 4 gives 64. These added (168 + 64) give 23a. Now 
make the proportion 232 : 100 :: 168 : x t and it is found that 72.4 is the percentage of metallic iron. In the same way the percentage 
of oxygen is found to be 27.5. The method shown in the above example gives the possible percentage in any ore or compound 
according to the chemical formulae given in the " Tables." Such purity as is indicated by the formulae is. however, very rarely 
and in many cases never met with. It follows, of course, that the percentage of the desirable element in the ore is reduced in 
proportion to the impurities present. 






>*^ 



IV.-INDEX TO TABLES. 



PAGE 

Actinolite 30, 74 

Albertke 74 

Albite 64 

Almandite 67 

Alum 22 

Aluminum 20 

Amethyst 60, 132 

Amianthus 30 

Ammonia Alum 22 

Amphibole 74 

Anhydrite 42 

Anthracite 46 

Ankerite 92 

Annabergite 122 

Antimony 22 

Antimony Glance 24 

Apatite 26 

Aragonite 42 

Argentiferous Cerussite 140 

Argentiferous Galena 140 



PAGE 

Argentiferous Pyrites 140 

Argentiferous Zinc Blende ..... 140 

Argentite 134 

Argillaceous Hematite 88 

Arsenic 28 

Arsenopyrite 28 

Asbestos 30, 74 

Asbestus 30 

Asbolite 52 

Asphalt 78 

Atacamite 58 

Auriferous Iron Pyrites 70 

Auriferous Galena 7 r 

Auriferous Zinc Blende 71 

Augite (Green) 128 

Augite (White). 128 

Aventurine Feldspar 65 

Azurite 56 

Barite 32 

163 



... ..PAGE 

Bauxite 20 

Bell Metal Ore 144 

Beryl 62 

Bismutite 36 

Bismuth 3». 34 

Bismuth Glance 34 

Bismuthinite • 34 

Bismuth Ochre 36 

Bismuth Sulphide 34 

Bituminous Coal . 48 

Bitumen 78 

Black Band Ore 92 

Black Copper Ore 58 

Black Copper Sulphide 54 

Black Jack 150 

Blue Malachite 56 

Bog. Iron Ore 90 

Bog Manganese 106 

Borate of Soda 36 

Bora jc 36 



TAG* 

Bornite 56 

Bo3tonite 100 

Braunite. 106 

Brittle Silver 134 

Bronoyrite 140 

Bronzite 128 

Brown Coal 48 

Brown Hematite 90 

Calamine 152 

Calaverite 70 

Calcareous Sinter 38 

Calcite (Calcium Carbonate) 38 

Calcium 38 

Calc Spar 38 

Caliche 122 

Calomel no 

Cannel Coal 48 

Capillary Pyrites. 120 

Carbuncle 67 

Cassiterite 144 

Celestite 42 

Cerargy rite. 138 

Cerussite 98 

Cervantite. 24 



INDEX TO TABLES.-Continued 

PAGB 

Chalcedony 133 

Chalcocite 54 

Chalcopyrite 54 

Chile Saltpetre 122 

China-clay 96 

Chloanthite 50, 116 

Chloride of Silver 58 

Chlorine 44 

Chlorites 100 

Chromate of Lead 46 

Chromite (Chromic Iron) 44 

Chromium... 44 

Chrysocolla 58 

Chrysotile 30, 100 

Cinnabar no 

Clay 64 

Clay-ironstone 92 

Coals .46 

Cobalt 50 

Cobalt Bloom 52 

Cobakite (Cobalt Glance) 50 

Cobalt Pyrites 52 

Cockscomb Pyrites 94 

Coke (Coking Coal) 46, 48, 49 

Coloradoite 112 

104 



PAGB 

Copper 54 

Copper Carbonate 5ft 

Copper Glance 54 

Copper Nickel 1 16 

Copper Pyrites 54 

Copper Silicate 58 

Copper Sulphide 54 

Corundum 60 

Crocoite 46 

Cryolite 20 

Cuprite 58 

Dark-red Silver Ore 136 

Diallage 1 28 

Diallogite 108 

Diamond 62 

Dolomite 40 

Dry Bone 152 

Dyscrasite 134 

Earthy Cobalt 52 

Electric Calamine 1 52 

Electro-silicon 81 

Embolite 138 

Emerald 62 



INDEX TO TABLES.-Continued. 



PAGE 

Emerald Nickel 118 

Emery 60 

Epidote 62 

Epsom Salts 103 

Erubescite 56 

Erythrite 52 

Feldspar 64 

Fire-clay 64 

Fire Opal 124 

Flos-ferri 42 

Fluorite 66 

Fluor-spar 66 

Fossil Iron Ore 88 

Franklinite 96, 154 

Freieslebenite 136 

Fuller's Earth 66 

Galena (Galenite) 98 

Garnet 66 

Garnierite 118 

Genthite 118 

German Silver 116 

Gersdorffite 120 

Gilsonite 76 



Goetbite 88 

Gold 68 

Grahamite • 7° 

Graphite 1* 

Gray Copper. 60 

Gypsum . 40 

Halite 72 

Halotrichite 22 

Hauntajayite 138 

Hausmannite 106 

Heavy Spar 3 s 

Hematite 84 

Hornblende 74 

Horn Silver 138 

Hubnerite 146 

Hydraulic Limestone 40 

Hydrocarbons 74 

Hydrozincite 152 

Hypersthene 128 

Ilmenite 94 

Infusorial Earth 80 

Iodine 122 

Iodyrite 140 

165 



PAGE 

Iridium 82 

Iridosmine 82 

Iron 82 

Iron Carbonate 92 

Iron Pyrites 94 

Iron Sulphide 94 

Iserine 94 

Isinglass... 112 

Itabiryte 86 

Jasper 133 

Jaspery Clay Iron-stone 88 

J^ 48 

Kalinlte .- 22 

Kaolin. 96 

Kaolinite 96 

Kermesite 24, 26 

Kidney Ore 84 

Lead 98 

Lead Carbonate 98 

Lead Sulphide 98 

Lenticular Iron Ore 88 

Light-red Silver Ore 136 

Lignite 48 



INDEX TO TABLES.-Contlnued. 



PACK 

Limestone 38 

Limonite 90 

Linnaeite. 52 

Lithographic Stone 39 

Magnesite 102 

Magnesium 100 

Magnetic Iron Pyrites 96 

Magnetic Iron Ore 84 

Magnetite 84 

Malachite 56 

Maltha 78 

Manganese 104 

Manganese Carbonate 108 

Manganese Silicate 108 

Manganese Spar 108 

Manganite 106 

Marble 38 

Marcasite 94 

Martite 86 

Melaconite 58 

Menaccanite 94 

Mendozite 22 

Mercury 108, no 

Mercury Chloride HO 



Mercury Telluride 112 

Mexican Onyx.. 38, 132 

Miargyrite 134 

Mica 112 

Micaceous Iron Ore 86 

Millerite 120 

Mineral Oil 78 

Mineral Tar 78 

Mispickel 28 

Molybdate of Lead 114 

Molybdenite 114 

Molybdenum 114 

Monazite 114 

Moon Stone 65 

Mountain Cork 30, 74 

Mountain Leather 30, 74 

Mountain Paper 74 

Mountain Wood 74 

Muscovite 112 

Nagyagite 70 

Natural Gas 80 

Niccolite z 16 

Nickel 116 

Nickel Arsenic. 122 1 

166 



PAGK 

Nickel Blende 120 

Nickel Carbonate 118 

Nickel Glance 120 

Nickeliferous Iron Pyrites 120 

Nickel Ochre 122 

Nickel Silver 116 

Nickel Sulphide 120 

Nitre 122 

Nitric Acid 123 

Noumeite 118 

Obsidian 124 

Odontolite 149 

Oligoclase • 64 

Onyx 38, 132 

Opal.. • 124 

Oriental Amethyst 60 

Oriental Emerald.. 62 

Orpiment 2 8 

Orthoclase • 64 

Ozokerite • • • • 7° 

Peach-blossom Ore 52 

Peacock Ore 56 

Pentlandite "8 



PAGE 

Petroleum 78 

Pitt Asphalt „ 78 

Phosphate Rock 26, 27, 126 

Phosphorite 26 

Plaster of Paris 40, 41 

Platinum 126 

Polybasite 136 

Potash Alum 22 

Potash Nitre.. 122 

Potstone 102 

Proustite 136 

Psilomelane 104 

Pumice 124 

Pyrargyrite 136 

Pyrites 94 

Pyrolusite 104 

Pyroxene 128 

Pyrrhotite 96 

Quartz 132 

Realgar 30 

Red Copper Oxide 58 

Red Ochre 88 

Red Oxide of Zinc. 154 



INDEX TO TABLES.-Continued. 

PAGK 

Red Shale Ore 88 

Rhodoch rosite 108 

Rhodonite 108 

Rock Salt 72 

Ruby 130 

Ruby Zinc 154 

Rutile 130 

Salt 72 

Saltpetre 122 

Sapphire 130 

Scheelite 148 

Semi-bituminous Coal 48 

Serpentine 30, too 

Siderite 92 

Silex 81 

Silica 132 

Silicined Wood. 133 

Silver 132 

Silver Chloride 138 

Silver Copper Glance 136 

Silver Glance 134 

Silver Sulphide 134 

Smaltite 50 

Smithsonite 152 

167 



PAGK 

Soapstone 102 

Soda Alum 22 

Soda Nitre 122 

Soft Hematite 86 

Spathic Iron Ore. 92 

Specular Iron Ore , .... 86 

Speiss Cobalt 50 

Sperrylite 120, 128 

Sphalerite 150 

Stalactite 38 

Stalagmite 38 

Stannite 144 

Steatite 102 

Stephanite 134 

Stibnite 24 

Stream Tin 144 

Stromeyerite 136 

Sulphur 142 

Sun Stone 65 

Sylvanite 70 

Tabular Spar 1 50 

Talc 102 

Telluride of Gold 70 

Tellurium 142 



PAGE 

Tennantite 60 

Tetradymite 36 

Tetrahedrite. 60, 140 

Thorium Sands 114 

Tin 144 

Ti ncal 36 

Tin Pyrites 144 

Tin Stone. 144 

Tin Sulphide 144 

Topaz. 146 

Travertine 38 

Tremolite • 74 

Tripolite 80 

Tungsten 148 

Turgite 88 



INDEX TO TABLES.-Continued. 

PAGE 

Turquois 148 

Uintahite 76 

Ullmannite 1 20 

Valentinite 24 

Variegated Copper Pyrites 56 

Velvet Iron Ore 88 

Volcanic Glass 124 

Vulpinite 43 

Wad 106 

White Antimony 24 

White Iron Pyrites 94 

Willcmite 152 

Wittichite 36 

JO 

AJLISdSAINn 

3 MA JO 



PAGB 

Wolframite 146 

Wollastonite 150 

Wulfenite 114 

Yellow Ochre 90 

Zaratite 118 

Zinc 150 

Zinc Blende 150 

Zinc Bloom 152 

Zinc Carbonate 152 

Ztncite 1 54 

Zinc Silicate 152 

Zinc Sulphide 150 

Zircon 154 



168 



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